Compositions for the detection of fluorocarbons and related articles, systems and methods

Abstract

Compositions, articles, systems, and methods for the detection of fluorocarbons are generally described. In certain embodiments, for example, sensing materials are described that include a bound multichromophore. The bound multichromophore can be capable of energy transport and / or diffusion between individual moieties of the bound multichromophore. In certain embodiments, for example, the bound multichromophore includes individual moieties that are linked via delocalized orbitals, such that the bound multichromophore is capable of energy transport and / or diffusion through each individual moiety of the bound multichromophore. Sensing materials that include bound multichromophores can be configured to detect the presence of an analyte, such as a fluoroalkyl species (e.g., perfluoroalkyl and / or polyfluoroalkyl materials). For example, in some embodiments, the bound multichromophore includes at least one chromophore that exhibits a change in electromagnetic radiation (e.g., light) emission in response to the presence of the analyte.

Description

[Technical Field]

[0001] Related Applications This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 385,728, entitled "Detection of Fluorocarbon Compounds," filed December 1, 2022, and U.S. Provisional Patent Application No. 63 / 503,979, entitled "Detection of PFAS," filed May 24, 2023, both of which are incorporated by reference in their entirety for all purposes.

[0002] Technical Field Compositions, articles, systems, and methods for the detection of fluorocarbons are generally described. [Background technology]

[0003] background Per- and polyfluoroalkyl substances (PFAS) are "forever chemicals" whose high chemical stability allows them to slowly accumulate over time in the environment and biological systems. Fluorinated materials have useful properties and are widely used in consumer products (e.g., food packaging, nonstick cookware, and lubricants) and as additives in firefighting foams, cleaning products, and personal care products. A study conducted by the U.S. Centers for Disease Control and Prevention (CDC) revealed that most people in the United States are exposed to PFAS concentrations that can lead to adverse health outcomes, such as thyroid disease, liver damage, reduced fertility, and even certain types of cancer. There are multiple types of PFAS, but the most common are "long-chain" perfluoroalkyl carboxylic acids (C n F 2n+1 COOH, n≧7) and perfluoroalkylsulfonic acids (C n F 2n+1SO3H, n ≥ 6) are particularly resistant to degradation and have a higher bioaccumulation potential than their "short-chain" analogues. In response, in 2016 the US Environmental Protection Agency (EPA) established a minimum combined concentration limit of 70 ng L-1 for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) in drinking water. -1 The U.S. issued a health advisory level of 70 ppt for PFOA and 70 ppt for PFOS in drinking water in 2019. These health advisory limits will be updated in 2022, and the current drinking water health advisory levels are 0.02 ppt for PFOA and 0.004 ppt for PFOS. While these latest advisory levels are currently only interim limits, they warn that some negative effects may occur at ultra-trace levels of PFOA and PFOS in water that are difficult to measure throughout the water distribution infrastructure.

[0004] Currently, EPA methods for detecting PFAS in the ng / L range utilize a combination of liquid chromatography and mass spectrometry. These methods offer accuracy and sensitivity, but are cost-prohibitive and require specialized laboratories with well-trained personnel. Recent research efforts have focused on developing rapid, portable, easy-to-use, and low-cost detection methods that would enable continuous environmental monitoring. However, sensors suitable for on-site detection are scarce and lack sufficient sensitivity and / or selectivity. In addition to the extremely low concentrations of PFAS in water, the complexity of real-world water samples, which typically contain various ions, biopolymers, humic acids, and / or organic oils or surfactants, makes PFAS detection, monitoring, and mitigation difficult.

[0005] Therefore, there is a need for improved compositions, articles, systems, and methods for the detection of fluorocarbons. Summary of the Invention [Means for solving the problem]

[0006] overview Compositions and related articles, systems, and methods for the detection of fluorocarbons are generally described. The subject matter of the present invention may include interrelated products, alternative solutions to a particular problem, and / or multiple different uses of one or more systems and / or articles.

[0007] This Summary introduces selected concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify critical or essential features of the claimed subject matter, nor is it intended to limit its scope.

[0008] According to certain embodiments, sensing materials are described. In some embodiments, the sensing material comprises a linked multichromophore including at least one chromophore that exhibits a change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the linked multichromophore is capable of energy transfer between individual moieties of the linked multichromophore.

[0009] In certain embodiments, the sensing material comprises a bound multichromophore comprising at least one chromophore that exhibits a change in electromagnetic radiation emission in response to protonation of the bound multichromophore by a fluoroalkyl substance, wherein the bound multichromophore is capable of energy transfer between individual moieties of the bound multichromophore.

[0010] According to some embodiments, the sensing material comprises a linked multichromophore comprising at least two chromophores that exhibit a ratiometric change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the linked multichromophore is capable of energy transfer between individual moieties of the linked multichromophore.

[0011] In certain embodiments, a method for detecting a fluoroalkyl substance is described. In some embodiments, the method includes exposing a bound multichromophore to a solution containing a fluoroalkyl substance and detecting a change in electromagnetic radiation emission of at least one chromophore of the bound multichromophore, wherein the at least one chromophore exhibits a change in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance.

[0012] According to some embodiments, a method of detecting a fluoroalkyl substance includes exposing a bound multichromophore to a solution containing the fluoroalkyl substance and detecting a change in electromagnetic radiation emission of at least one chromophore of the bound multichromophore, wherein the at least one chromophore exhibits a change in electromagnetic radiation emission in response to protonation of the bound multichromophore by the fluoroalkyl substance.

[0013] In certain embodiments, a method for detecting a fluoroalkyl substance includes exposing a bound multichromophore to a solution containing the fluoroalkyl substance and detecting a ratiometric change in electromagnetic radiation emission of at least two chromophores of the bound multichromophore, wherein the at least two chromophores exhibit a ratiometric change in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance.

[0014] According to certain embodiments, an article is described. In some embodiments, the article includes a sensing material including a bound multichromophore including at least one chromophore that exhibits a change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the bound multichromophore is capable of energy transfer between individual moieties of the bound multichromophore.

[0015] In certain embodiments, a system is described. In some embodiments, the system includes a source of a solution and a sensing material including a bound multichromophore that includes at least one chromophore that exhibits a change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the bound multichromophore is capable of energy transfer between individual moieties of the bound multichromophore.

[0016] One aspect of the present disclosure is a method for detecting per- and polyfluoroalkyl substances (PFAS) in an aqueous sample, comprising: providing an aqueous sample containing PFAS; adding an amplifying fluorescent polymer (AFP) to the aqueous sample; allowing the AFP and the PFAS to form an AFP-PFAS complex; detecting the presence of PFAS in the aqueous sample by the absorption and / or fluorescence spectra of the AFP-PFAS complex; The method includes:

[0017] In one embodiment of the disclosed method, the AFP comprises a poly(p-phenylene ethynylene) backbone and / or a polyfluorene backbone.

[0018] In one embodiment of the disclosed method, the AFP is poly(p-phenylene ethynylene) (PPE), polyfluorene (PF), and / or fluorinated poly(p-phenylene ethynylene) ( F It contains a backbone containing PPE.

[0019] In one embodiment of the disclosed method, the AFP comprises a PFAS selector, and the PFAS selector has the structure: [ka] and / or the PFAS selector comprises a pyridine (Py) having the structure: [ka] The compound includes a thiophene-functionalized pyridine (Py*) having the formula:

[0020] One aspect of the disclosure herein is a composition comprising a light-absorbing polymer and a dye, wherein the light-absorbing polymer and / or dye comprises a perfluoroalkane group, the perfluoroalkane group comprising at least 25 w:w% fluorine, and wherein the composition produces a sensing emission characteristic in response to a PFAS analyte.

[0021] In one embodiment of the disclosed composition, the dye is a small molecule or a polymer.

[0022] In one embodiment of the disclosed composition, the dye is selected from fluorous squaraine (F-Sq), fluorous oxazine (F-Ox), fluorous perylene bisimide (F-FBI), and mixtures and / or conjugates thereof.

[0023] In one embodiment of the disclosed composition, the light-absorbing polymer is PPE (43 w:w% fluorine) and / or F It contains a conjugated polymer containing PPE (61w:w% fluorine).

[0024] In one embodiment of the disclosed composition, either or both of the light-absorbing polymer and the dye comprise a Bronsted acid.

[0025] In one embodiment of the disclosed composition, either or both of the light-absorbing polymer and the dye comprise a Bronsted base.

[0026] In one embodiment of the disclosed composition, the PFAS analyte is a Bronsted acid.

[0027] In one embodiment of the disclosed composition, the perfluoroalkane group contains greater than 30 w:w%, 35 w:w%, 40 w:w%, or 50 w:w% fluorine.

[0028] In one embodiment of the disclosed composition, the light-absorbing polymer is a conjugated polymer.

[0029] In one embodiment of the disclosed composition, the emission sensing signature responsive to the PFAS analyte is a change in the ratio of two emissions.

[0030] In one embodiment of the disclosed composition, the emission sensing signature responsive to the PFAS analyte is a change in emission intensity at a particular wavelength.

[0031] In one embodiment of the disclosed composition, the emission sensing signature responsive to the PFAS analyte is a change in emission intensity having a lifetime greater than 10 nanoseconds.

[0032] In one embodiment of the disclosed composition, the emission detection characteristic responsive to the PFAS analyte is an increase in emission intensity.

[0033] In one embodiment of the disclosed composition, the emission sensing characteristic responsive to the PFAS analyte is a decrease in emission intensity.

[0034] In one embodiment of the disclosed composition, the emission sensing signature responsive to PFAS analytes arises from the acidity of the perfluoroalkane group.

[0035] In one embodiment of the disclosed composition, the emission sensing signature responsive to a PFAS analyte is derived from an exciplex.

[0036] In one embodiment of the disclosed composition, the emission sensing signature responsive to a PFAS analyte is detected in an aqueous solution.

[0037] In one embodiment of the disclosed composition, the PFAS analyte is detected at less than 200 parts per billion in aqueous solution.

[0038] One aspect of the present disclosure is a system comprising the disclosed compositions, where the system continuously monitors water for the presence of PFAS.

[0039] In one embodiment of the disclosed system, the system includes a surface that includes a light-absorbing polymer and a dye.

[0040] In one embodiment of the disclosed system, the system comprises a suspension of particles in water, the particles comprising a light-absorbing polymer and a dye.

[0041] In one embodiment of the disclosed system, the system further comprises a means for concentrating the PFAS analyte.

[0042] In one embodiment of the disclosed system, the system is capable of detecting PFAS analytes at concentrations of less than 1 part per billion in water.

[0043] In one embodiment of the disclosed system, the system is capable of detecting PFAS analytes at concentrations of less than 10 parts per trillion in water.

[0044] In the following detailed description, reference is made to the accompanying drawings, which form a part of this application and which show, by way of illustration, specific exemplary implementations. Other implementations are possible without departing from the scope of this disclosure. Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying drawings. In cases where the specification and any document incorporated by reference includes conflicting and / or inconsistent disclosure, the present specification shall control.

[0045] Non-limiting embodiments of the present invention are described by way of example with reference to the accompanying drawings, which are schematic and not intended to be to scale. In the drawings, each identical or nearly identical component shown is typically represented by a single numeral. For clarity, not every component is labeled in every drawing, and not every component of every embodiment of the present invention is shown unless illustration is necessary for those skilled in the art to understand the invention. [Brief explanation of the drawings]

[0046] [Figure 1A] FIG. 1A shows a cross-sectional schematic of a sensing material comprising a film containing bound multichromophores, according to one particular embodiment.

[0047] [Figure 1B] FIG. 1B shows a cross-sectional schematic of a sensing material comprising multiple particles containing bound multichromophores, according to certain embodiments.

[0048] [Figure 2] FIG. 2 shows a cross-sectional schematic view of an article including a substrate and a sensing material disposed on at least a portion of the substrate, according to certain embodiments.

[0049] [Figure 3A] FIG. 3A shows a cross-sectional schematic view of an article including a substrate and a sensing material disposed on at least a portion of the substrate, wherein the substrate and sensing material include a plurality of pores, according to certain embodiments.

[0050] [Figure 3B] FIG. 3B shows a schematic top view of the article shown in FIG. 3A, according to certain embodiments.

[0051] [Figure 4] FIG. 4 shows a cross-sectional schematic view of an article including a substrate and a sensing material disposed on at least a portion of the substrate, where the substrate comprises particles, according to certain embodiments.

[0052] [Figure 5] 5A-5B show schematic diagrams depicting a method comprising exposing a film of sensing material comprising bound multichromophores to a solution comprising a fluoroalkyl substance, according to certain embodiments.

[0053] [Figure 6]6A-6B show schematic diagrams depicting another method comprising exposing a film of sensing material containing bound multichromophores to a solution containing a fluoroalkyl substance, according to certain embodiments.

[0054] [Figure 7] 7A-7B show schematic diagrams depicting a method comprising exposing a plurality of particles of a sensing material comprising bound multichromophores to a solution comprising a fluoroalkyl substance, according to certain embodiments.

[0055] [Figure 8] 8A-8B show schematic diagrams depicting a method comprising exposing a substrate and a sensing material comprising an attached multichromophore disposed on the substrate to a solution comprising a fluoroalkyl substance, according to certain embodiments.

[0056] [Figure 9] 9A-9B show schematic diagrams illustrating another method comprising exposing a substrate and a sensing material comprising an attached multichromophore disposed on the substrate to a solution comprising a fluoroalkyl substance, according to certain embodiments.

[0057] [Figure 10] 10A-10C show schematic diagrams illustrating a method according to certain embodiments, comprising exposing a substrate and a sensing material comprising bound multichromophores disposed on the substrate to a solution comprising a fluoroalkyl substance, wherein the substrate and sensing material comprise a plurality of pores.

[0058] [Figure 11] 11A-11B show schematic diagrams illustrating a method according to certain embodiments, comprising exposing a sensing material comprising a substrate and a bound multichromophore disposed on the substrate to a solution comprising a fluoroalkyl substance, wherein the substrate comprises particles.

[0059] [Figure 12]FIG. 12 shows a schematic diagram of a system including a source of solution and a sensing material including bound multichromophores, according to certain embodiments.

[0060] [Figure 13-1] Figure 13 shows the chemical structure of a fluorous conjugated polymer (x=0.80, y=0.20) and a conceptual scheme of the mechanism for the detection of PFAS in water, according to certain embodiments, where diffusion of perfluorooctanoic acid (PFOA) from water into the polymer induces protonation of the pyridine moiety, causing a change in the release of the polymer. [Figure 13-2] Same as above.

[0061] [Figure 14A] FIG. 14A shows a synthetic route to highly fluorous polyfluorene (x=0.80, y=0.20) according to certain embodiments.

[0062] [Figure 14B-1] FIG. 14B shows a synthetic route to fluorous poly(p-phenyleneethynylene) (x=0.80, y=0.20) according to certain embodiments. [Figure 14B-2] Same as above.

[0063] [Figure 15A] FIG. 15A shows the absorption (dotted line) and fluorescence (solid line) spectra of PPE-Py in benzotrifluoride solution, a spin-cast film of PPE-Py, and PPE-Py conjugated polymer nanoparticles (CPdots), according to certain embodiments.

[0064] [Figure 15B] FIG. 15B shows the absorption (dotted line) and fluorescence (solid line) spectra of FPPE-Py and a spin-cast film of FPPE-Py in benzotrifluoride solution, according to certain embodiments.

[0065] [Figure 15C]FIG. 15C shows the absorption (dotted line) and fluorescence (solid line) spectra of PF-Py in benzotrifluoride solution, a spin-cast film of PF-Py, and PF-Py CPdots, according to certain embodiments.

[0066] [Figure 15D] FIG. 15D shows the absorption (dotted line) and fluorescence (solid line) spectra of PPE-Py* in benzotrifluoride solution, a spin-cast film of PPE-Py*, and PPE-Py*CPdot, according to certain embodiments.

[0067] [Figure 15E] FIG. 15E shows the absorption (dotted line) and fluorescence (solid line) spectra of FPPE-Py* and a spin-cast film of FPPE-Py* in benzotrifluoride solution, according to certain embodiments.

[0068] [Figure 15F] FIG. 15F shows the absorption (dotted lines) and fluorescence (solid lines) spectra of PF-Py* in benzotrifluoride solution, a spin-cast film of PF-Py*, and PF-Py*CPdot, according to certain embodiments.

[0069] [Figure 16A] FIG. 16A shows the fluorescence spectrum of a PPE-Py thin film upon exposure to an aqueous solution of PFOA, and a corresponding fluorescence photograph of the thin film, according to certain embodiments.

[0070] [Figure 16B] FIG. 16B shows the fluorescence spectrum of a PPE-Py* thin film upon exposure to an aqueous solution of PFOA, and a corresponding fluorescence photograph of the thin film, according to certain embodiments.

[0071] [Figure 16C]FIG. 16C shows the fluorescence spectrum of a PF-Py thin film upon exposure to an aqueous solution of PFOA, and a corresponding fluorescence photograph of the thin film, according to certain embodiments.

[0072] [Figure 16D] FIG. 16D shows the fluorescence spectrum of a PF-Py* thin film upon exposure to an aqueous solution of PFOA, and a corresponding fluorescence photograph of the thin film, according to certain embodiments.

[0073] [Figure 17A] FIG. 17A shows the change in fluorescence intensity of PPE-Py thin films after exposure to PFOA in Milli-Q water, deionized (DI) water, and well water (average values ​​of three different films, error bars represent standard deviation), according to certain embodiments.

[0074] [Figure 17B] FIG. 17B shows the change in fluorescence intensity of PPE-Py* thin films after exposure to PFOA in Milli-Q water, DI water, and well water (average values ​​of three different films, error bars represent standard deviation), according to certain embodiments.

[0075] [Figure 17C] FIG. 17C shows the change in fluorescence intensity of PF-Py thin films after exposure to PFOA in Milli-Q water, DI water, and well water (average values ​​of three different films, error bars represent standard deviation), according to certain embodiments.

[0076] [Figure 17D] FIG. 17D shows the change in fluorescence intensity of PF-Py* thin films after exposure to PFOA in Milli-Q water, DI water, and well water (average values ​​of three different films, error bars represent standard deviation), according to certain embodiments.

[0077] [Figure 18A]FIG. 18A shows the change in fluorescence intensity of a PPE-Py thin film after exposure to perfluorooctyl sulfonate (PFOS) in Milli-Q water and well water, according to certain embodiments (average of three different measurements, error bars represent standard deviation).

[0078] [Figure 18B] FIG. 18B shows the change in fluorescence intensity of PPE-Py*CPdot after exposure to PFOS in Milli-Q water and well water (average of three different measurements, error bars represent standard deviation), according to certain embodiments.

[0079] [Figure 19A] FIG. 19A shows dynamic light scattering (DLS) measurements of an aqueous dispersion of CPdots, according to certain embodiments.

[0080] [Figure 19B] FIG. 19B shows a transmission electron microscope (TEM) image of PPE-Py*CPdot, according to certain embodiments.

[0081] [Figure 20A] FIG. 20A shows the fluorescence spectrum of PPE-Py CPdots upon exposure to an aqueous solution of PFOA, and a fluorescence photograph of the corresponding CPdot dispersion, according to certain embodiments.

[0082] [Figure 20B] FIG. 20B shows the fluorescence spectrum of PPE-Py*CPdot upon exposure to an aqueous solution of PFOA, and a fluorescence photograph of the corresponding CPdot dispersion, according to certain embodiments.

[0083] [Figure 20C] FIG. 20C shows the fluorescence spectrum of PF-Py CPdots upon exposure to an aqueous solution of PFOA, and a fluorescence photograph of the corresponding CPdot dispersion, according to certain embodiments.

[0084] [Figure 20D]FIG. 20D shows the fluorescence spectrum of PF-Py*CPdot upon exposure to an aqueous solution of PFOA, and a fluorescence photograph of the corresponding CPdot dispersion, according to certain embodiments.

[0085] [Figure 21A] FIG. 21A shows the change in fluorescence intensity of PPE-Py CPdots after exposure to PFOA in Milli-Q water and well water (average values ​​of three different CPdot dispersions, error bars represent standard deviation), according to certain embodiments.

[0086] [Figure 21B] FIG. 21B shows the change in fluorescence intensity of PPE-Py*CPdot after exposure to PFOA in Milli-Q water and well water (average values ​​of three different CPdot dispersions, error bars represent standard deviation), according to certain embodiments.

[0087] [Figure 21C] FIG. 21C shows the change in fluorescence intensity of PF-Py CPdots after exposure to PFOA in Milli-Q water and well water (average values ​​of three different CPdot dispersions, error bars represent standard deviation), according to certain embodiments.

[0088] [Figure 21D] FIG. 21D shows the change in fluorescence intensity of PF-Py*CPdot after exposure to PFOA in Milli-Q water and well water (average values ​​of three different CPdot dispersions, error bars represent standard deviation), according to certain embodiments.

[0089] [Figure 22] FIG. 22 shows a table of molecular weights and polydispersity indices of synthetic polymers, according to certain embodiments.

[0090] [Figure 23] FIG. 23 shows a table of photophysical data according to certain embodiments.

[0091] [Figure 24-1] Figure 24 shows the chemical structures of fluorous poly(p-phenyleneethynylene) and fluorous dye, as well as a conceptual scheme of the mechanism for the detection of PFAS in water, according to certain embodiments, in which diffusion of PFOA from water into the polymer disrupts the π-π interaction between the dye and the conjugated polymer, interrupting electron transfer (ET) based on electron exchange. [Figure 24-2] Same as above.

[0092] [Figure 25A] FIG. 25A shows the fluorescence spectra of PPE / F-Sq in thin films as a function of dye loading, according to certain embodiments.

[0093] [Figure 25B] FIG. 25B shows the fluorescence spectrum of PPE / F-Sq in a thin film upon exposure to an aqueous solution of PFOA, according to certain embodiments.

[0094] [Figure 25C] Figure 25C shows the change in fluorescence intensity of PPE / F-Sq and FPPE / F-Sq thin films after exposure to PFOA in Milli-Q water for 1 hour (average values ​​of three different films, error bars represent standard deviation) according to certain embodiments.

[0095] [Figure 26A] FIG. 26A shows the change in fluorescence intensity of thin films of PPE and F-Sq after 1 hour of exposure to aqueous solutions of PFOA in Milli-Q water (solid line) and well water (patterned), according to certain embodiments (average value of three different films, error bars represent standard deviation).

[0096] [Figure 26B] Figure 26B shows the change in fluorescence intensity of thin films of PPE and F-Sq after 1 hour of exposure to aqueous PFOS solutions in Milli-Q water (solid line) and well water (patterned), according to certain embodiments (average value of three different films, error bars represent standard deviation).

[0097] [Figure 27A] FIG. 27A shows DLS measurements of a water dispersion of CPdots, according to certain embodiments.

[0098] [Figure 27B] FIG. 27B shows a TEM image of PPE / F-Sq CPdots, according to certain embodiments.

[0099] [Figure 27C] FIG. 27C shows the fluorescence spectra of PPE / F-Sq CPdots as a function of dye loading, according to certain embodiments.

[0100] [Figure 28A] Figure 28A shows the change in CPdot fluorescence intensity of PPE and F-Sq after 1 hour of exposure to aqueous solutions of PFOA in Milli-Q water (solid line) and well water (patterned), according to certain embodiments (average values ​​of three different CPdot dispersions, error bars represent standard deviation).

[0101] [Figure 28B] Figure 28B shows the change in CPdot fluorescence intensity of PPE and F-sq after 1 hour of exposure to aqueous PFOS solutions in Milli-Q water (solid line) and well water (patterned), according to certain embodiments (average values ​​of three different CPdot dispersions, error bars represent standard deviation).

[0102] [Figure 29A] FIG. 29A shows the absorbance (solid line) and fluorescence (dotted line) spectra of PPE and the fluorous dye F-Sq, according to certain embodiments.

[0103] [Figure 29B] FIG. 29B shows the fluorescence spectra of thin films of PPE / F-Sq dye formulations as a function of dye loading, according to certain embodiments.

[0104] [Figure 29C] FIG. 29C shows the absorbance (solid line) and fluorescence (dotted line) spectra of PPE and the fluorous dye F-Ox, according to certain embodiments.

[0105] [Figure 29D] FIG. 29D shows the fluorescence spectra of thin films of PPE / F-Ox dye formulations as a function of dye loading, according to certain embodiments.

[0106] [Figure 29E] FIG. 29E shows the absorbance (solid line) and fluorescence (dotted line) spectra of PPE and the fluorous dye F-PBI, according to certain embodiments.

[0107] [Figure 29F] FIG. 29F shows the fluorescence spectra of thin films of PPE / F-PBI dye formulations as a function of dye loading, according to certain embodiments.

[0108] [Figure 30] FIG. 30 shows the fluorescence spectrum of a thin film of PPE / Sq after exposure to aqueous octanoic acid for 1 hour, according to certain embodiments.

[0109] [Figure 31] FIG. 31 shows the proton nuclear magnetic resonance (H NMR) spectrum (400 MHz, 298 K, CDCl) of PPE, according to certain embodiments.

[0110] [Figure 32] FIG. 32 shows the fluorine nuclear magnetic resonance (F NMR) spectrum (376 MHz, 298 K, CDCl) of PPE, according to certain embodiments.

[0111] [Figure 33] FIG. 33 outlines a synthetic route to fluorous poly(p-phenyleneethynylene), according to certain embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0112] Detailed Description Compositions, articles, systems, and methods for the detection of fluorocarbons are generally described. In certain embodiments, for example, sensing materials are described that include a bound multichromophore. The bound multichromophore can be capable of energy transport and / or diffusion between individual moieties of the bound multichromophore. In certain embodiments, for example, the bound multichromophore includes individual moieties that are linked via delocalized orbitals, such that the bound multichromophore is capable of energy transport and / or diffusion through each individual moiety of the bound multichromophore. Sensing materials that include a bound multichromophore can be configured to detect the presence of an analyte, such as a fluoroalkyl species (e.g., perfluoroalkyl and / or polyfluoroalkyl materials). For example, in some embodiments, the bound multichromophore includes at least one chromophore that exhibits a change in electromagnetic radiation emission (e.g., luminescence) in response to the presence of the analyte. In some embodiments, the change in electromagnetic radiation emission can be detected to determine the presence of the analyte. In certain embodiments, the presence of the analyte can be determined at ultratrace (e.g., ppb or ppt) levels.

[0113] In certain embodiments, the bound multichromophore comprises a moiety that can be protonated by an analyte. In response to protonation of the bound multichromophore by the analyte, at least one chromophore of the bound multichromophore can exhibit a change in electromagnetic radiation (e.g., light) emission. In some embodiments, the change in electromagnetic radiation emission of the at least one chromophore is a wavelength shift of the emission peak to a lower energy emission. According to certain embodiments, the presence of the analyte is detected upon detection of a change in the electromagnetic radiation emission of the at least one chromophore.

[0114] According to some embodiments, the bound multichromophore comprises a dye. In response to an analyte changing the organization of at least a portion of the bound multichromophore, at least two chromophores of the bound multichromophore can exhibit a ratiometric change in electromagnetic radiation (e.g., light) emission. In certain embodiments, for example, the analyte displaces at least a portion of the dye from the bound multichromophore. In some embodiments, the ratiometric change in electromagnetic radiation emission comprises an increase in the emission peak of the first chromophore and a decrease in the emission peak of the second chromophore. According to some embodiments, the presence of the analyte is detected upon detection of a ratiometric change in the electromagnetic radiation emission of the at least two chromophores.

[0115] The sensing material comprising the bound multichromophore can be in any of a variety of suitable forms. For example, in some embodiments, the sensing material comprising the bound multichromophore is a film (e.g., a thin film). In other embodiments, the sensing material comprising the bound multichromophore is a plurality of particles. In still other embodiments, the sensing material comprising the bound multichromophore is disposed (e.g., coated) on a substrate. The sensing material comprising the bound multichromophore disposed on the substrate can be in the form of a film, filter, and / or membrane. In some embodiments, the substrate is a particle, and the sensing material comprising the bound multichromophore is disposed (e.g., coated) on the particle. In certain embodiments, the sensing material is incorporated into a system including a source of solution such that the solution flows from the source and is exposed to the sensing material.

[0116] Also described herein are methods for detecting an analyte. In some embodiments, for example, a sensing material including a bound multichromophore is exposed to a solution containing the analyte. In certain embodiments, the analyte is detected by detecting a change in electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore, wherein at least one chromophore of the bound multichromophore exhibits a change in electromagnetic radiation emission in response to the presence of the analyte.

[0117] According to certain embodiments, the sensing material comprises a coupled multichromophore. As used herein, the term "coupled multichromophore" refers to a material comprising at least a first individual moiety and a second individual moiety that are coupled together, and the material can comprise or host multiple chromophores. The term "coupled," as used herein, indicates a level of interaction between the individual moieties of the coupled multichromophore that allows an excited state generated in the coupled multichromophore to transfer between the individual moieties. In some embodiments, each individual moiety of the coupled multichromophore can be coupled such that each individual moiety is bonded together (e.g., covalently bonded or otherwise chemically bonded). In certain embodiments, for example, the coupled multichromophore is or comprises a conjugated polymer.

[0118] As used herein, the term "individual moiety" refers to a portion of a material (e.g., a linked multichromophore) that is larger than a single atom and is separated from a different individual moiety by at least one other atom, defining a chromophore. In some embodiments, for example, an individual moiety of a linked multichromophore includes one or more repeat units of a polymer, a portion of a polymer, a portion of a repeat unit of a polymer, a portion, a portion of a portion, a small molecule (e.g., a dye), and a portion of a small molecule. In some cases, these individual moieties each include sufficient atomic configurations and atomic combinations to perform a specific function related to the disclosure herein (e.g., absorbing and / or emitting electromagnetic radiation), and each individual moiety is separated from other individual moieties by sufficient atomic configurations to allow each individual moiety to perform its own function largely independently of other moieties, even if those functions are interrelated. For example, in some embodiments, one individual moiety can be involved in absorbing electromagnetic radiation, and another individual moiety can emit in response to that absorption, resulting in energy (e.g., excitons and / or electrons) transfer between the individual moieties. Of course, the atomic configuration, connectivity, and proximity of one individual moiety to other individual moieties (e.g., nearest neighboring individual moieties) may affect the molecular and electronic structure of either or both individual moieties, but not so much as to negate the function of the individual moieties. This concept, i.e., that different individual moieties of a material interact with electromagnetic radiation and with each other in this manner, is well known and understood by those skilled in the art, but they would not be able to arrive at the disclosed and claimed configurations without the teachings and guidance of this disclosure. Examples of individual moieties and energy transfer between individual moieties are provided more fully below.

[0119] As used herein, the term "chromophore" refers to a chemical group of a molecule that absorbs electromagnetic radiation of a particular frequency or frequency profile, range, or pattern (e.g., light or other electromagnetic radiation, including ultraviolet radiation, infrared radiation, and / or radiation that extends beyond or entirely outside the visible, ultraviolet, or infrared regions) and emits electromagnetic radiation of a particular frequency or frequency profile, range, or pattern. In some cases, the absorption and emission of electromagnetic radiation by the chemical group of a molecule imparts subtractive and / or additive color to the molecule. In some embodiments, the frequencies at which a chromophore absorbs electromagnetic radiation and the frequencies at which the chromophore emits electromagnetic radiation may be similar, but the frequencies at which the chromophore emits electromagnetic radiation may be lower than the frequencies at which the chromophore absorbs electromagnetic radiation. For example, in some embodiments, photons absorbed by a chromophore create an excited state that releases some energy through vibration, solvent reorganization, and / or other processes, and the emitted photons are lower in energy. In other embodiments, the frequencies at which the chromophore absorbs electromagnetic radiation and the frequencies at which it emits electromagnetic radiation vary more significantly, in which case the radiation patterns or ranges of the absorption and emission frequencies do not overlap but are distinctly different. For example, in certain embodiments where energy is transferred from a chromophore that normally emits at a higher frequency to a chromophore that emits at a lower frequency, a large frequency shift can be observed. As used herein, the term "electromagnetic radiation" is given its ordinary meaning in the art and refers to waves of the electromagnetic field that propagate through space and carry momentum and electromagnetic radiation energy, including radio waves, microwaves, infrared waves, (visible) light, ultraviolet waves, X-rays, and gamma rays. In some embodiments, the bound multichromophore is preferably excited by ultraviolet and / or visible light.

[0120] According to some embodiments, the bound multichromophore is capable of energy transfer and / or diffusion between the individual moieties of the bound multichromophore. In certain embodiments, for example, the bound multichromophore includes at least two individual moieties (e.g., at least two chromophores) linked via atomic structure links that provide delocalized orbitals. In some embodiments, the at least two individual moieties are capable of energy (e.g., excitons and / or electrons) transfer and / or diffusion from a first individual moiety (e.g., a first chromophore) of the bound multichromophore to a second individual moiety (e.g., a second chromophore) of the bound multichromophore bound to the first individual moiety. In certain embodiments, the first individual moiety is directly adjacent to the second individual moiety. In some embodiments, bound multichromophores capable of energy transfer between the individual moieties of the bound multichromophore may be advantageously used to detect an analyte of interest by rapidly diffusing excitons and / or electrons sampling each individual moiety of the bound multichromophore. In certain embodiments, for example, an analyte of interest may interact with a bound multichromophore (e.g., an individual site of a bound multichromophore), thereby creating a lower energy trapping state that captures a rapidly diffusing exciton and / or electron.

[0121] In some embodiments, the bound multichromophore comprises at least one chromophore that exhibits a change in electromagnetic radiation (e.g., light) emission in response to the presence of an analyte. In certain embodiments, the analyte is a fluoroalkyl substance, as described in more detail herein. In some embodiments, the analyte (e.g., the fluoroalkyl substance) interacts with the bound multichromophore (e.g., an individual portion of the bound multichromophore), thereby creating a lower energy trapping state that captures rapidly diffusing excitons and / or electrons, thereby causing the bound multichromophore (e.g., an individual portion of the bound multichromophore that has not interacted with the analyte and / or an individual portion of the bound multichromophore that has interacted with the analyte) to exhibit a change in electromagnetic radiation emission.

[0122] According to some embodiments, the bound multichromophore comprises a polymer. For example, in certain embodiments, the bound multichromophore comprises a conjugated polymer. As used herein, the term "conjugated polymer" is given its ordinary meaning in the art and refers to a macromolecule characterized by a backbone chain with alternating double and single bonds, such that overlapping p orbitals create a delocalized π-electron system. In certain embodiments, bound multichromophores comprising conjugated polymers may advantageously facilitate the transport and / or diffusion of energy between individual moieties of the bound multichromophore. In some embodiments, as described in more detail herein, bound multichromophores comprising conjugated polymers are amplifying fluorescent polymers used in sensors (e.g., fluorescent sensors) to enhance the sensitivity of the sensors to analytes (e.g., fluoroalkyl substances).

[0123] In certain embodiments where the bound multichromophore comprises a polymer, one or more individual moieties of the bound multichromophore comprise one or more repeat units of the polymer and / or portions of one or more repeat units of the polymer. In some embodiments, for example, the bound multichromophore is capable of energy transfer and / or diffusion between one or more repeat units of the polymer and one or more other individual moieties of the bound multichromophore (e.g., one or more other repeat units of the polymer).

[0124] According to certain embodiments, the polymer is porous. In some embodiments, the use of a bound multichromophore containing porous polymer advantageously facilitates the absorption of an analyte (e.g., a fluoroalkyl substance) to the bound multichromophore. In certain embodiments, for example, the fluoroalkyl substance is absorbed by the bound multichromophore containing porous polymer, and thus, when the bound multichromophore is exposed to the fluoroalkyl substance, the fluoroalkyl substance diffuses into one or more pores of the porous polymer.

[0125] According to certain embodiments, the porosity of a porous polymer can be characterized by the Brunauer-Emmett-Teller (BET) surface area of ​​the porous polymer. The porous polymer can have any of a variety of suitable BET surface areas. In some embodiments, for example, the porous polymer can have a BET surface area of ​​100 m 2 / g or greater, 200m 2 / g or greater, 300m 2 / g or greater, 400m 2 / g or greater, 500m 2 / g or greater, 600m 2 / g or greater, 700m 2 / g or greater, 800m 2 / g or greater, or 900m 2 / g or greater. In certain embodiments, the porous polymer has a BET surface area of ​​1,000 m 2 / g or less, 900m 2 / g or less, 800m 2 / g or less, 700m 2 / g or less, 600m 2 / g or less, 500m 2 / g or less, 400m 2 / g or less, 300m 2 / g or less, or 200m 2 / g or less. Combinations of the above ranges are possible (e.g., the porous polymer has a BET surface area of ​​100 m 2 / g or greater and 1,000m 2 Porous polymers having a BET surface area of ​​400 m / g or less are 2 / g or greater and 600m 2 / g or less). Other ranges are possible. As described in more detail herein, the polymer may have limited porosity (50 m 2 / g) and still be able to absorb the analyte.

[0126] The bound multichromophore can comprise any of a variety of suitable polymers. In some embodiments, for example, the polymer comprises a statistical polymer, a block polymer, a copolymer thereof, and / or a combination thereof. In certain embodiments, the polymer comprises a backbone comprising an acrylate, a styrene, a vinyl ether, a norbornene, an arylene, a cellulose, an arylene ether, an arylene amine, a diene, a siloxane, an alkene, a conjugate thereof, and / or a combination thereof. In certain embodiments, the chromophore of the bound multichromophore is pendant to the backbone of the polymer.

[0127] According to certain embodiments, the polymer is a fluorescent polymer. In some embodiments, for example, the polymer is an amplifying fluorescent polymer.

[0128] According to some embodiments, the attached multichromophore comprises a polyarylene, a poly(arylene vinylene), a poly(thiophene), a poly(phenylene), a poly(fluorene), a poly(phenylene), a poly(arylene ethynylene), a poly(phenylene ethynylene), a copolymer thereof, and / or a combination thereof. Other polymers are possible. In some embodiments, for example, the attached multichromophore comprises a poly(arylene ether), which is not conjugated but allows energy transfer within the polymer.

[0129] In certain embodiments, the bound multichromophore comprises a collection of small molecules. In certain embodiments, for example, the bound multichromophore comprises an oil (e.g., a hydrocarbon, a siloxane, a halocarbon, a fluorocarbon), an alkane (e.g., a fluoroalkane), a cyclodextrin, a calixarene, a cavitand, a triptycene, an iptycene, a Lewis acid, a Lewis base, a Bronsted base, a metal ion, a macrocycle, conjugates thereof, and / or combinations thereof. Other small molecules are also possible.

[0130] The linked multichromophores can be loosely or tightly bound in the aggregate. In the case of tightly bound aggregates, it is preferable to have aggregates that produce enhanced emission intensity (more efficient emission) compared to the individual chromophores. These processes are called aggregation-induced emission or J-aggregate formation. Aggregation-induced emission refers to the aggregation stiffening of the molecules, preventing the dissipation of excited-state energy through conformational dynamic processes. J-aggregates are formed when electronic coupling increases the emission rate, thus competing with other non-radiative processes for greater efficiency.

[0131] In certain embodiments, the sensing material (e.g., the bound multichromophore) is configured to absorb the fluoroalkyl substance. In some embodiments, for example, the bound multichromophore is at least partially fluorinated such that the fluorinated domains of the bound multichromophore favorably distribute the fluoroalkyl substance within the sensing material. In some embodiments, exposing a sensing material comprising an at least partially fluorinated bound multichromophore to the fluoroalkyl substance causes the fluoroalkyl substance to diffuse into the sensing material.

[0132] In some embodiments, the attached multichromophore comprises at least one fluoroalkyl group. In certain embodiments, where the attached multichromophore comprises a conjugated polymer, the at least one fluoroalkyl group advantageously prevents close stacking between portions of the conjugated polymer. The at least one fluoroalkyl group of the attached multichromophore can comprise fluorine in any of a variety of suitable amounts. In some embodiments, for example, the at least one fluoroalkyl group of the attached multichromophore comprises fluorine in an amount of 25 weight percent (wt.%) or more, 30 wt.% or more, 35 wt.% or more, 40 wt.% or more, 45 wt.% or more, 50 wt.% or more, 55 wt.% or more, 60 wt.% or more, 65 wt.% or more, or 70 wt.% or more, based on the total weight of the at least one fluoroalkyl group of the attached multichromophore. In certain embodiments, the at least one fluoroalkyl group of the attached multichromophore comprises fluorine in an amount of 75 wt.% or less, 70 wt.% or less, 65 wt.% or less, 60 wt.% or less, 55 wt.% or less, 50 wt.% or less, 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, or 30 wt.% or less, based on the total weight of the at least one fluoroalkyl group of the attached multichromophore. Combinations of the above ranges are also possible (e.g., at least one fluoroalkyl group of the attached multichromophore contains 25 wt.% or more and 75 wt.% or less fluorine, based on the total weight of at least one fluoroalkyl group of the attached multichromophore; at least one fluoroalkyl group of the attached multichromophore contains 50 wt.% or more and 55 wt.% or less fluorine, based on the total weight of at least one fluoroalkyl group of the attached multichromophore). Other ranges are also possible.

[0133] The bound multichromophore can include fluorine in any of a variety of suitable amounts. In some embodiments, for example, the bound multichromophore includes fluorine in an amount of 25 weight percent (wt.%) or more, 30 wt.% or more, 35 wt.% or more, 40 wt.% or more, 45 wt.% or more, 50 wt.% or more, 55 wt.% or more, 60 wt.% or more, 65 wt.% or more, or 70 wt.% or more, based on the total weight of the bound multichromophore. In certain embodiments, the bound multichromophore comprises 75 wt.% or less, 70 wt.% or less, 65 wt.% or less, 60 wt.% or less, 55 wt.% or less, 50 wt.% or less, 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, or 30 wt.% or less fluorine, based on the total weight of the bound multichromophore. Combinations of the above ranges are also possible (e.g., the bound multichromophore comprises 25 wt.% or more and 75 wt.% or less fluorine, based on the total weight of the bound multichromophore; the bound multichromophore comprises 50 wt.% or more and 55 wt.% or less fluorine, based on the total weight of the bound multichromophore). Other ranges are also possible.

[0134] In certain embodiments, the bound multichromophore comprises a moiety that can be protonated by a fluoroalkyl substance. In some embodiments in which the bound multichromophore comprises a moiety that can be protonated by a fluoroalkyl substance, one or more individual sites of the bound multichromophore comprise a moiety that can be protonated by a fluoroalkyl substance and / or a portion of a moiety that can be protonated by a fluoroalkyl substance. In some embodiments, for example, the bound multichromophore is capable of energy transfer and / or diffusion between the moiety that can be protonated by a fluoroalkyl substance and one or more other individual sites of the bound multichromophore (e.g., one or more repeat units of a polymer).

[0135] According to some embodiments, the moiety that can be protonated by a fluoroalkyl material is a Bronsted base. As used herein, the term "Bronsted base" is given its ordinary meaning in the art and refers to a moiety that can be protonated by a proton (H + ) refers to a species that can accept a fluoroalkyl group. In some embodiments, for example, the linked multichromophore includes a nitrogen (N)-containing moiety that can be protonated by a fluoroalkyl substance. The linked multichromophore can include any of a variety of suitable N-containing moieties. In some embodiments, for example, the linked multichromophore includes a pyridine-containing moiety. In certain embodiments, the linked multichromophore includes a pyridine- and thiophene-containing moiety (e.g., a thiophene-functionalized pyridine-containing moiety). Without being bound by theory, linked multichromophores including pyridine- and thiophene-containing moieties may advantageously exhibit a greater change (e.g., shift) in electromagnetic radiation (e.g., light) emission (e.g., compared to linked multichromophores including pyridine-containing moieties) due to the π-electron delocalization characteristic of thiophene.

[0136] According to some embodiments, the attached multichromophore has the structure: [ka] The pyridine-containing moiety has the formula:

[0137] Those skilled in the art will recognize that there are several other moieties that can be protonated, including, for example, pyrazines, amines, imines, triazines, and nitrogen-containing conjugated heterocycles.

[0138] According to certain embodiments, the interaction between the moiety that can be protonated by a fluoroalkyl substance (e.g., an N-containing moiety such as a pyridine-containing moiety) and the fluoroalkyl substance is a bonding interaction. In some embodiments, for example, the interaction between the moiety that can be protonated by a fluoroalkyl substance and the fluoroalkyl substance is an ionic bond resulting from a proton transfer reaction.

[0139] In some embodiments, at least one chromophore of the bound multichromophore exhibits a change in electromagnetic radiation (e.g., light) emission in response to protonation of the bound multichromophore by a fluoroalkyl substance. In certain embodiments, for example, the fluoroalkyl substance interacts with an individual portion of the bound multichromophore (e.g., a moiety that can be protonated by the fluoroalkyl substance), and thus the fluoroalkyl substance protonates the individual portion of the bound multichromophore, thereby causing the entire bound multichromophore (e.g., the individual portion of the bound multichromophore that has not interacted with the fluoroalkyl substance and the individual portion of the bound multichromophore that has interacted with the fluoroalkyl substance) to exhibit a change in electromagnetic radiation emission.

[0140] In certain embodiments, the change in the electromagnetic radiation (e.g., light) emission of at least one chromophore is a wavelength shift of the emission peak to a lower energy emission. In some embodiments, for example, the emission peak shifts by 10 nm or more, 50 nm or more, 100 nm or more, or 150 nm or more to a lower energy emission. In certain embodiments, the emission peak shifts by 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less to a lower energy emission. Combinations of the above ranges are also possible (e.g., the emission peak shifts by 10 nm or more and 200 nm or less to a lower energy emission, or the emission peak shifts by 50 nm or more and 100 nm or less to a lower energy emission). Other ranges are also possible.

[0141] According to certain embodiments, the change in electromagnetic radiation (e.g., light) emission in response to protonation of the bound multichromophore by the fluoroalkyl substance can be at least partially ratiometric. In certain embodiments, for example, the change in electromagnetic radiation of the emission peak and the occurrence of a lower energy emission peak can be at least partially ratiometric.

[0142] In certain embodiments, the bound multichromophore comprises a dye. As used herein, the term "dye" is given its ordinary meaning in the art and refers to a molecule capable of absorbing electromagnetic radiation in the ultraviolet and / or visible range of the electromagnetic spectrum. In certain embodiments, the bound multichromophore comprises a dye, one or more individual moieties of the bound multichromophore comprise the dye. In some embodiments, for example, the bound multichromophore is capable of energy transport and / or diffusion between the dye and one or more other individual moieties of the bound multichromophore (e.g., one or more repeat units of a polymer).

[0143] The bound multichromophore can include any of a variety of suitable dyes. In certain embodiments, the dye can accept energy from one or more individual sites of the bound multichromophore. In some embodiments, for example, the dye comprises a small molecule and / or a polymer. In certain embodiments, the dye comprises a squaraine, oxazine, perylene bisimide, coumarin, cyanine, conjugates thereof, and / or combinations thereof. Other dyes are possible.

[0144] According to some embodiments, the dye is at least partially fluorinated. In certain embodiments, the fluorinated domains of the dye favorably distribute the fluoroalkyl substance within the sensing material. For example, in some embodiments, exposing a bound multichromophore comprising an at least partially fluorinated dye to a fluoroalkyl substance causes the fluoroalkyl substance to diffuse into the bound multichromophore.

[0145] In some embodiments, the pigment comprises at least one fluoroalkyl group. The at least one fluoroalkyl group of the pigment can comprise any of a variety of suitable amounts of fluorine. In some embodiments, for example, the at least one fluoroalkyl group of the pigment comprises 25 wt.% or more, 30 wt.% or more, 35 wt.% or more, 40 wt.% or more, 45 wt.% or more, 50 wt.% or more, 55 wt.% or more, 60 wt.% or more, 65 wt.% or more, or 70 wt.% or more of fluorine, based on the total weight of the at least one fluoroalkyl group of the pigment. In certain embodiments, the at least one fluoroalkyl group of the dye contains 75 wt.% or less, 70 wt.% or less, 65 wt.% or less, 60 wt.% or less, 55 wt.% or less, 50 wt.% or less, 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, or 30 wt.% or less of fluorine, relative to the total weight of the at least one fluoroalkyl group of the dye. Combinations of the above ranges are also possible (e.g., the at least one fluoroalkyl group of the dye contains 25 wt.% or more and 75 wt.% or less of fluorine, relative to the total weight of the at least one fluoroalkyl group of the dye; the at least one fluoroalkyl group of the dye contains 50 wt.% or more and 55 wt.% or less of fluorine, relative to the total weight of the at least one fluoroalkyl group of the dye). Other ranges are also possible.

[0146] The pigment may include any of a variety of suitable amounts of fluorine. In some embodiments, for example, the pigment includes 25 wt.% or more, 30 wt.% or more, 35 wt.% or more, 40 wt.% or more, 45 wt.% or more, 50 wt.% or more, 55 wt.% or more, 60 wt.% or more, 65 wt.% or more, or 70 wt.% or more fluorine based on the total weight of the pigment. In certain embodiments, the pigment comprises 75 wt.% or less, 70 wt.% or less, 65 wt.% or less, 60 wt.% or less, 55 wt.% or less, 50 wt.% or less, 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, or 30 wt.% or less of fluorine, based on the total weight of the pigment. Combinations of the above ranges are also possible (e.g., the pigment comprises 25 wt.% or more and 75 wt.% or less of fluorine, based on the total weight of the pigment; the pigment comprises 50 wt.% or more and 55 wt.% or less of fluorine, based on the total weight of the pigment). Other ranges are also possible.

[0147] The bound multichromophore can include the dye in any of a variety of suitable amounts. In some embodiments, for example, the bound multichromophore includes 0.1 wt.% or more, 0.2 wt.% or more, 0.3 wt.% or more, 0.4 wt.% or more, 1 wt.% or more, 2 wt.% or more, 3 wt.% or more, or 4 wt.% or more of the dye, based on the total weight of the bound multichromophore. In some embodiments, the bound multichromophore includes 5 wt.% or less, 4 wt.% or less, 3 wt.% or less, 2 wt.% or less, 1 wt.% or less, 0.5 wt.% or less, 0.4 wt.% or less, 0.3 wt.% or less, or 0.2 wt.% or less of the dye, based on the total weight of the bound multichromophore. Combinations of the above ranges are also possible (e.g., the bound multichromophore comprises the dye in an amount of 0.1 wt.% or more and 5 wt.% or less, based on the total weight of the bound multichromophore; the bound multichromophore comprises the dye in an amount of 0.3 wt.% or more and 0.5 wt.% or less, based on the total weight of the bound multichromophore). Other ranges are also possible.

[0148] According to some embodiments, the linked multichromophore comprises at least two chromophores that exhibit a ratiometric change in electromagnetic radiation (e.g., light) emission in response to the presence of a fluoroalkyl substance. As used herein, the term "ratiometric" refers to providing information using the ratio of the intensities of two or more emission frequencies. In some embodiments, this ratio provides greater precision in detecting an analyte than individual emission intensities can provide as a single signal. In certain embodiments, this ratio can provide information regarding the amount or concentration of the analyte.

[0149] In certain embodiments, the fluoroalkyl substance can interact with the bound multichromophore and change the organization of at least a portion of the bound multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the bound multichromophore, causing a disruption of electron transfer between one or more individual sites of the bound multichromophore and the dye, resulting in at least two chromophores of the bound multichromophore exhibiting a ratiometric change in electromagnetic radiation emission. In some embodiments, the displacement is small, and the dye is not physically removed from the matrix containing the bound multichromophore, but is displaced such that the orbital overlap between the dye and the chromophores of the bound multichromophore is reduced.

[0150] According to some embodiments, a first chromophore of the at least two chromophores may be able to donate energy to a second chromophore of the at least two chromophores. Without being bound by theory, in certain embodiments in which the bound multichromophore comprises a polymer and a dye, the polymer may act as a light-harvesting unit (e.g., a donor), which provides energy to the dye (e.g., an acceptor), amplifying light emission from the dye. In certain embodiments, the polymer and dye may have no or negligible spectral overlap.

[0151] In some embodiments, a first chromophore of the at least two chromophores exhibits an increase in electromagnetic radiation (e.g., light) emission in response to the presence of a fluoroalkyl substance. In certain embodiments in which the bound multichromophore comprises a polymer and a dye, for example, the first chromophore corresponding to the polymer (e.g., corresponding to one or more repeat units of the polymer) exhibits an increase in electromagnetic radiation emission in response to the fluoroalkyl substance interacting with the bound multichromophore and changing the organization of at least a portion of the bound multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the bound multichromophore, thereby causing disruption of electron transfer between the polymer (e.g., one or more repeat units of the polymer) and the dye.

[0152] The lifetime of the increase in electromagnetic radiation (e.g., light) emission of the first chromophore can be any of a variety of suitable values. In some embodiments, for example, the lifetime of the increase in electromagnetic radiation emission of the first chromophore is 1 microsecond or more, 2 microseconds or more, 5 microseconds or more, 10 microseconds or more, 20 microseconds or more, 50 microseconds or more, 100 microseconds or more, or 500 microseconds or more. In certain embodiments, the lifetime of the increase in electromagnetic radiation emission of the first chromophore is 1 millisecond or less, 500 microseconds or less, 100 microseconds or less, 50 microseconds or less, 20 microseconds or less, 10 microseconds or less, 5 microseconds or less, or 2 microseconds or less. Combinations of the above ranges are also possible (e.g., the lifetime of the increase in electromagnetic radiation emission of the first chromophore is 1 microsecond or longer and 1 millisecond or shorter, the lifetime of the increase in electromagnetic radiation emission of the first chromophore is 50 microseconds or longer and 200 microseconds or shorter). Other ranges, including ranges greater than 1 millisecond, are also possible.

[0153] According to certain embodiments, the second chromophore of the at least two chromophores exhibits a decrease in electromagnetic radiation (e.g., light) emission in response to the presence of the fluoroalkyl substance. In certain embodiments where the bound multichromophore comprises a polymer and a dye, for example, the second chromophore corresponding to the dye exhibits a decrease in electromagnetic radiation emission in response to the fluoroalkyl substance interacting with at least a portion of the bound multichromophore and changing the organization of the bound multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the bound multichromophore, thereby causing a disruption of electron transfer between the polymer (e.g., one or more repeat units of the polymer) and the dye.

[0154] The lifetime of the decay of the electromagnetic radiation (e.g., light) emission of the second chromophore can be any of a variety of suitable values. In some embodiments, for example, the lifetime of the decay of the electromagnetic radiation emission of the second chromophore is 1 nanosecond or more, 2 nanoseconds or more, 5 nanoseconds or more, 10 nanoseconds or more, 20 nanoseconds or more, 50 nanoseconds or more, 100 nanoseconds or more, or 500 nanoseconds or more. In certain embodiments, the lifetime of the decay of the electromagnetic radiation emission of the second chromophore is 1 microsecond or less, 500 nanoseconds or less, 100 nanoseconds or less, 50 nanoseconds or less, 20 nanoseconds or less, 10 nanoseconds or less, 5 nanoseconds or less, or 2 nanoseconds or less. Combinations of the above ranges are also possible (e.g., the lifetime of the second chromophore's electromagnetic radiation emission decay is 1 nanosecond or longer and 1 millisecond or shorter, the lifetime of the second chromophore's electromagnetic radiation emission decay is 50 nanoseconds or longer and 200 nanoseconds or shorter). Other ranges, including ranges greater than 1 millisecond, are also possible.

[0155] The attached multichromophores may be of various suitable weight average molecular weights (M wIn certain embodiments, for example, the attached multichromophore is a molecular and / or polymeric assembly having a weight average molecular weight of 500 g / mol or greater, 1,000 g / mol or greater, 5,000 g / mol or greater, 10,000 g / mol or greater, 50,000 g / mol or greater, 100,000 g / mol or greater, 500,000 g / mol or greater, 1,000,000 g / mol or greater, or 1,500,000 g / mol or greater. In some embodiments, the attached multichromophore is a molecular and / or polymeric assembly having a weight average molecular weight of 2,000,000 g / mol or less, 1,500,000 g / mol or less, 1,000,000 g / mol or less, 500,000 g / mol or less, 100,000 g / mol or less, 50,000 g / mol or less, 10,000 g / mol or less, 5,000 g / mol or less, or 1,000 g / mol or less. Combinations of the above ranges are possible (e.g., the bound multichromophore has a weight average molecular weight of 500 g / mol or greater and 2,000,000 g / mol or less, the bound multichromophore has a weight average molecular weight of 50,000 g / mol or greater and 100,000 g / mol or less). Other ranges are also possible. The weight average molecular weight of the bound multichromophore can be determined by gel permeation chromatography.

[0156] The attached multichromophores may be of various suitable number average molecular weights (M n) In certain embodiments, for example, the attached multichromophore has a number average molecular weight of 500 g / mol or greater, 1,000 g / mol or greater, 5,000 g / mol or greater, 10,000 g / mol or greater, 50,000 g / mol or greater, 100,000 g / mol or greater, or 500,000 g / mol or greater. In some embodiments, the attached multichromophore has a number average molecular weight of 1,000,000 g / mol or less, 500,000 g / mol or less, 100,000 g / mol or less, 50,000 g / mol or less, 10,000 g / mol or less, 5,000 g / mol or less, or 1,000 g / mol or less. Combinations of the above ranges are also possible (e.g., the bound multichromophore has a number average molecular weight of 500 g / mol or greater and 1,000,000 g / mol or less, the bound multichromophore has a number average molecular weight of 50,000 g / mol or greater and 100,000 g / mol or less). Other ranges are also possible. The number average molecular weight of the bound multichromophore can be determined by gel permeation chromatography.

[0157] The linked multichromophore can have any of a variety of suitable polydispersity indices. In certain embodiments, for example, the linked multichromophore has a polydispersity index of 1 or higher, 1.5 or higher, 2 or higher, or 2.5 or higher. In some embodiments, the linked multichromophore has a polydispersity index of 3 or lower, 2.5 or lower, 2 or lower, or 1.5 or lower. Combinations of the above ranges are also possible (e.g., the linked multichromophore has a polydispersity index of 1 or higher and 3 or lower, the linked multichromophore has a polydispersity index of 2 or higher and 2.5 or lower). Other ranges are also possible. The polydispersity index of the linked multichromophore can be determined by dividing the weight-average molecular weight of the linked multichromophore by the number-average molecular weight of the linked multichromophore.

[0158] The bound multichromophore can have any of a variety of suitable quantum yields. As used herein, the term "quantum yield" is given its ordinary meaning in the art and refers to the ratio of the number of photons emitted by the bound multichromophore to the number of photons absorbed by the bound multichromophore. The percent quantum yield of the bound multichromophore can be determined according to Equation 1 (eq. 1) shown below.

number

[0159] In certain embodiments, the quantum yield of the bound multichromophore is advantageously high so that the bound multichromophore has a long excited-state lifetime and a low non-radiative rate. According to certain embodiments, the bound multichromophore has a quantum yield of 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, or 70% or more. In some embodiments, the bound multichromophore has a quantum yield of 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, or 35% or less. Combinations of the above ranges are also possible (e.g., the bound multichromophore has a quantum yield of 30% or higher and 75% or lower, the bound multichromophore has a quantum yield of 50% or higher and 55% or lower). Other ranges are also possible.

[0160] According to certain embodiments, the quantum yield of the attached multichromophore may change upon exposure to a fluoroalkyl substance. In some embodiments, for example, the quantum yield of the attached multichromophore decreases upon exposure to a fluoroalkyl substance. In other embodiments, the quantum yield of the attached multichromophore increases upon exposure to a fluoroalkyl substance.

[0161] The conjugated multichromophores can be synthesized by methods known to those skilled in the art. In certain embodiments, for example, the conjugated multichromophores can be synthesized by one or more polymerization reactions of one or more monomers (e.g., Suzuki polymerization, Sonogashira polymerization, free radical polymerization, cationic polymerization, metal-catalyzed polymerization, ring-opening polymerization, and / or condensation polymerization).

[0162] The sensing material can have any of a variety of suitable forms. In some embodiments, for example, the sensing material comprises a film (e.g., a thin film) that includes bound multichromophores. Figure 1A shows a cross-sectional schematic diagram of sensing material 102a that comprises a film 106 that includes bound multichromophores 104, according to one particular embodiment.

[0163] The film can have any of a variety of suitable thicknesses. Referring to FIG. 1A , for example, film 106 can have thickness 110a. In certain embodiments, the film has an average thickness of 0.1 nanometers or more, 0.5 nanometers or more, 1 nanometer or more, 10 nanometers or more, 100 nanometers or more, 1 micrometer or more, 10 micrometers or more, 100 micrometers or more, 1 millimeter or more, or 1 centimeter or more. In some embodiments, the film has an average thickness of 10 centimeters or less, 1 centimeter or less, 1 millimeter or less, 100 micrometers or less, 10 micrometers or less, 1 micrometer or less, 100 nanometers or less, 10 nanometers or less, 1 nanometer or less, or 0.5 nanometers or less. Combinations of the above ranges are also possible (e.g., a film having an average thickness of 0.1 nanometers or greater and 10 centimeters or less, a film having an average thickness of 100 nanometers or greater and 1 micrometer or less). Other ranges are also possible. The average thickness of the film can be determined by electron microscopy techniques (e.g., scanning electron microscopy and / or transmission electron microscopy).

[0164] 1A, film 106 including bound multichromophores 104 is depicted as a smooth layer of uniform thickness, however, one skilled in the art will understand that this is merely for illustrative purposes and that the thickness of the film may have a certain roughness and / or may vary in thickness according to some embodiments. In some embodiments, for example, the film is of a relatively uniform thickness (e.g., within ±25% of the average thickness of the film, within ±10% of the average thickness of the film, within ±1% of the average thickness of the film).

[0165] The film can be formed by any of a variety of suitable methods. In some embodiments, for example, the film is formed by spin-casting, spin-coating, and / or dip-coating a solution of the bound multichromophore.

[0166] In certain embodiments, the sensing material comprises a plurality of particles comprising bound multichromophores. Figure 1B shows a cross-sectional schematic diagram of sensing material 102b comprising a plurality of particles 108 (e.g., particles 108a and 108b) comprising bound multichromophores 104, according to certain embodiments. In some embodiments, the plurality of particles of sensing material have a larger surface area, for example, compared to a film of sensing material, thereby advantageously increasing detection of fluoroalkyl substances.

[0167] According to some embodiments, the particles may be magnetic so that they can be manipulated using a magnetic field.

[0168] Each particle of the plurality of particles can have any of a variety of suitable shapes. In some embodiments, each particle of the plurality of particles has a spherical shape, for example, as shown in Figure 1B. In other embodiments, one or more particles of the plurality of particles have an angular, cylindrical, cubic, ellipsoidal, and / or fibrous shape, etc.

[0169] According to some embodiments, the plurality of particles comprises a plurality of microparticles. The term "microparticle" is used herein in a manner consistent with its ordinary meaning in the art. A microparticle is a particle having a largest characteristic dimension (e.g., largest diameter) of 1 micrometer to 100 micrometers. The largest characteristic dimension of a particle generally refers to the longest dimension from a first surface of the particle to a second surface substantially opposite the first surface. As an example, referring to FIG. 1B, particle 108b has largest characteristic dimension 112a. According to some embodiments, the largest characteristic dimension of a microparticle is 1 micrometer to 10 micrometers, 10 micrometers to 20 micrometers, 20 micrometers to 30 micrometers, 30 micrometers to 50 micrometers, 50 micrometers to 70 micrometers, or 70 micrometers to 100 micrometers. Combinations of the above ranges are also possible (e.g., 30 micrometers to 70 micrometers or 20 micrometers to 100 micrometers). Other ranges are also possible. The largest characteristic dimension of a microparticle can be determined by electron microscopy techniques (eg, scanning electron microscopy and / or transmission electron microscopy).

[0170] In certain embodiments, the plurality of particles comprises a plurality of nanoparticles. The term "nanoparticle" is used herein in a manner consistent with its ordinary meaning in the art. A nanoparticle is a particle having a largest characteristic dimension of 1 nanometer to 1 micrometer. According to some embodiments, the largest characteristic dimension of a nanoparticle is 1 nanometer to 100 nanometers, 100 nanometers to 200 nanometers, 200 nanometers to 300 nanometers, 300 nanometers to 500 nanometers, 500 nanometers to 700 nanometers, or 700 nanometers to 1 micrometer. Combinations of the above ranges are also possible (e.g., 300 nanometers to 700 nanometers or 200 nanometers to 1 micrometer). Other ranges are also possible. The largest characteristic dimension of a nanoparticle can be determined by electron microscopy techniques (e.g., scanning electron microscopy and / or transmission electron microscopy).

[0171] According to some embodiments, the plurality of particles comprises a combination of particles having different largest characteristic dimensions. According to some embodiments, for example, the plurality of particles comprises at least one microparticle and at least one nanoparticle.

[0172] The plurality of particles can be formed by any of a variety of suitable methods, in some embodiments, for example, the plurality of particles are formed by adding a non-aqueous solution of the bound multichromophore to water under sonication, followed by evaporation of the non-aqueous solvent.

[0173] In certain embodiments, the analyte described herein is a fluoroalkyl substance. As used herein, the term "fluoroalkyl substance" refers to a molecule containing an alkyl group in which one or more hydrogens are replaced with fluorine. The fluoroalkyl substance can be any of a variety of suitable fluoroalkyl substances. In certain embodiments, the fluoroalkyl substance is a perfluoroalkyl substance or a polyfluoroalkyl substance (PFAS). In certain embodiments, the fluoroalkyl substance includes 2-(N-methyl-perfluorooctanesulfonamido)acetic acid, perfluorobutanesulfonic acid, perfluorohexanesulfonic acid, perfluoroheptanoic acid, perfluorooctanesulfonic acid, perfluoromethylheptanesulfonic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, conjugates thereof, and / or combinations thereof. Other fluoroalkyl substances are also possible.

[0174] According to some embodiments, the fluoroalkyl material is a Bronsted acid. As used herein, the term "Bronsted acid" is given its ordinary meaning in the art and refers to a compound that is capable of reacting with a proton (H + ) refers to a species that can donate

[0175] The sensing material can have any of a variety of suitable sensitivities. In certain embodiments, the sensing material can detect the presence of a fluoroalkyl substance at parts per million (ppm) levels. In some embodiments, for example, the sensing material can detect the presence of a fluoroalkyl substance with a sensitivity of 1000 ppm or less, 100 ppm or less, or 10 ppm or less. In certain embodiments, the sensing material can detect the presence of a fluoroalkyl substance with a sensitivity of 1 ppm or more, 10 ppm or more, or 100 ppm or more. Combinations of the above ranges are also possible (e.g., the sensing material can detect the presence of a fluoroalkyl substance at 1000 ppm or less and with a sensitivity of 1 ppm or more, or the sensing material can detect the presence of a fluoroalkyl substance at 100 ppm or less and with a sensitivity of 10 ppm or more). Other ranges are also possible.

[0176] In some embodiments, the sensing material is capable of detecting the presence of a fluoroalkyl substance at parts per billion (ppb) levels, for example, the sensing material is capable of detecting the presence of a fluoroalkyl substance with a sensitivity of 1000 ppb or less, 900 ppb or less, 800 ppb or less, 700 ppb or less, 600 ppb or less, 500 ppb or less, 400 ppb or less, 300 ppb or less, 200 ppb or less, 100 ppb or less, 50 ppb or less, or 10 ppb or less. In certain embodiments, the sensing material can detect the presence of fluoroalkyl substances with a sensitivity of 1 ppb or more, 10 ppb or more, 50 ppb or more, 100 ppb or more, 200 ppb or more, 300 ppb or more, 400 ppb or more, 500 ppb or more, 600 ppb or more, 700 ppb or more, 800 ppb or more, or 900 ppb or more. Combinations of the above ranges are also possible (for example, the sensing material can detect the presence of fluoroalkyl substances at a sensitivity of 1000 ppb or less and 1 ppb or more, the sensing material can detect the presence of fluoroalkyl substances at a sensitivity of 500 ppb or less and 400 ppb or more). Other ranges are also possible.

[0177] According to certain embodiments, the sensing material is capable of detecting the presence of fluoroalkyl substances at parts per trillion (ppt) levels. In some embodiments, for example, the sensing material is capable of detecting the presence of fluoroalkyl substances with a sensitivity of 1000 ppt or less, 900 ppt or less, 800 ppt or less, 700 ppt or less, 600 ppt or less, 500 ppt or less, 400 ppt or less, 300 ppt or less, 200 ppt or less, 100 ppt or less, 50 ppt or less, or 10 ppt or less. In certain embodiments, the sensing material can detect the presence of fluoroalkyl substances with a sensitivity of 1 ppt or more, 10 ppt or more, 50 ppt or more, 100 ppt or more, 200 ppt or more, 300 ppt or more, 400 ppt or more, 500 ppt or more, 600 ppt or more, 700 ppt or more, 800 ppt or more, or 900 ppt or more. Combinations of the above ranges are also possible (for example, the sensing material can detect the presence of fluoroalkyl substances at 1000 ppt or less and 1 ppt or more sensitivity, the sensing material can detect the presence of fluoroalkyl substances at 500 ppt or less and 400 ppt or more sensitivity). Other ranges are also possible.

[0178] According to certain embodiments, an article is described. In some embodiments, the article comprises a sensing material comprising a bound multichromophore, as described in more detail elsewhere herein.

[0179] According to some embodiments, the article is a film comprising bound multichromophores as described in more detail elsewhere herein with respect to FIG. 1A.

[0180] In certain embodiments, the article further includes a substrate. In some embodiments, for example, the sensing material is disposed on at least a portion of the substrate. Figure 2 shows a cross-sectional schematic view of an article 202a including a substrate 204 and a sensing material 102' including a bound multichromophore 104 disposed on at least a portion of the substrate 204, according to certain embodiments. According to some embodiments, as shown in Figure 2, the sensing material 102' is disposed on a surface 206 of the substrate 204 such that the sensing material 102' coats the surface 206 of the substrate 204. In certain embodiments, the sensing material 102' is chemically grafted to the surface 206 of the substrate 204.

[0181] According to some embodiments, the substrate and / or sensing material disposed on the surface of the substrate comprises a plurality of pores. Figure 3A shows a cross-sectional schematic view of an article 202b including a substrate 204' and a sensing material 102" including bound multichromophores 104, according to certain embodiments, where the substrate 204' and sensing material 102" comprise a plurality of pores 210 (e.g., pores 210a, 210b, and 210c). Figure 3B shows a top-view schematic view of article 202b, according to certain embodiments, where the cross-section shown in Figure 3A is taken along dotted line 3A.

[0182] 3A, the sensing material 102'' is disposed on the surface 206 of the substrate 204' such that the sensing material 102'' coats the surface 206 of the substrate 204'. In certain embodiments, the sensing material 102'' is chemically grafted to the surface 206 of the substrate 204'.

[0183] In certain embodiments in which the substrate and / or sensing material comprises a plurality of pores, the article can be a filter and / or a membrane. With reference to Figures 3A-3B, for example, article 202b can be a filter and / or a membrane.

[0184] Each pore of the plurality of pores can have any of a variety of suitable shapes. In some embodiments, each pore of the plurality of pores has a circular shape, for example, as shown in Figure 3B. In other embodiments, one or more pores of the plurality of pores have an oval, square, rectangular, triangular, etc. shape.

[0185] The plurality of pores can have any of a variety of suitable maximum characteristic dimensions. The maximum characteristic dimension of a pore generally refers to the longest dimension from a first surface of the pore to a second surface substantially opposite the first surface. As an example, referring to FIG. 3B , pore 210a has maximum characteristic dimension 112b. According to certain embodiments, each pore of the plurality of pores has a maximum characteristic dimension of 2 nanometers or more, 10 nanometers or more, 100 nanometers or more, 500 nanometers or more, 1 micrometer or more, 10 micrometers or more, or 50 micrometers or more. In some embodiments, each pore of the plurality of pores has a maximum characteristic dimension of 100 micrometers or less, 50 micrometers or less, 10 micrometers or less, 1 micrometer or less, 500 nanometers or less, 100 nanometers or less, 100 nanometers or less, or 10 nanometers or less. Combinations of the above ranges are also possible (e.g., each pore of the plurality of pores has a maximum characteristic dimension of 2 nanometers or more and 100 micrometers or less, each pore of the plurality of pores has a maximum characteristic dimension of 500 nanometers or more and 10 micrometers or less). Other ranges are also possible.

[0186] The substrate can have any of a variety of suitable thicknesses. Referring to Figures 2-3A, for example, substrate 204 (e.g., substrate 204 in Figure 2 and substrate 204' in Figure 3A) has a thickness 110b. In certain embodiments, the substrate has an average thickness of 0.1 micrometer or more, 1 micrometer or more, 10 micrometers or more, 100 micrometers or more, 1 millimeter or more, 1 centimeter or more, or 10 centimeters or more. In some embodiments, the substrate has an average thickness of 1 meter or less, 10 centimeters or less, 1 centimeter or less, 1 millimeter or less, 100 micrometers or less, 10 micrometers or less, or 1 micrometer or less. Combinations of the above ranges are also possible (e.g., the substrate has an average thickness of 0.1 micrometers or greater and 1 meter or less, the substrate has an average thickness of 100 micrometers or greater and 1 millimeter or less). Other ranges are also possible.

[0187] 2-3A, substrate 204 (e.g., substrate 204 in FIG. 2 and substrate 204′ in FIG. 3A) is depicted as a smooth layer of uniform thickness, but one skilled in the art will understand that this is merely for illustrative purposes and that the thickness of the substrate may have a particular roughness and / or may vary in thickness, according to some embodiments. In some embodiments, for example, the substrate is of a relatively uniform thickness (e.g., within ±25% of the average thickness of the substrate, within ±10% of the average thickness of the substrate, or within ±1% of the average thickness of the substrate).

[0188] The sensing material disposed on the surface of the substrate can have any of a variety of suitable thicknesses. With reference to Figures 2-3A, for example, the sensing material 102 (e.g., sensing material 102' in Figure 2 and sensing material 102" in Figure 3A) disposed on the surface 206 of the substrate 204 (e.g., substrate 204 in Figure 2 and substrate 204' in Figure 3A) can have a thickness 110a. In certain embodiments, the sensing material disposed on the surface of the substrate has an average thickness as described in more detail herein with respect to the film of sensing material comprising bound multichromophores, as shown in Figure 1A. In some embodiments, for example, the sensing material disposed on the surface of the substrate has an average thickness equal to or greater than 0.1 nanometers and equal to or less than 10 centimeters.

[0189] 2-3A, sensing material 102 (e.g., sensing material 102′ in FIG. 2 and sensing material 102″ in FIG. 3A) disposed on surface 206 of substrate 204 (e.g., substrate 204 in FIG. 2 and substrate 204′ in FIG. 3A) is depicted as a smooth layer of uniform thickness; however, one skilled in the art will understand that this is merely for illustrative purposes and that the thickness of the sensing material disposed on the surface of the substrate may have a particular roughness and / or may vary in thickness, according to some embodiments. In some embodiments, the sensing material disposed on the surface of the substrate is of a relatively uniform thickness (e.g., within ±25% of the average thickness of the sensing material, within ±10% of the average thickness of the sensing material, within ±1% of the average thickness of the sensing material) across at least a majority of the surface of the substrate on which the sensing material is disposed (e.g., equal to or greater than 75% of the surface area of ​​the surface of the substrate on which the sensing material is disposed, equal to or greater than 90% of the surface area of ​​the surface of the substrate on which the sensing material is disposed, equal to or greater than 99% of the surface area of ​​the surface of the substrate).

[0190] The substrate can comprise any of a variety of suitable materials. In some embodiments, for example, the substrate comprises glass, ceramic, polymer, cellulose, nitrocellulose, metal, metal oxide, concrete, zeolite, mesoporous silicate, anodized alumina filter, and / or combinations thereof. In certain embodiments, the substrate comprises an optical fiber, an optical cavity, an optical waveguide, and / or a diffraction grating. In certain embodiments, the substrate comprises a fabric, a woven fabric, and / or a nanofiber mat. In some embodiments, the substrate comprises a filter material comprising a fiber, one or more polymers, glass, ceramic, metal oxide, and / or combinations thereof.

[0191] In certain embodiments, the substrate comprises a particle. Figure 4 shows a cross-sectional schematic view of an article 202c including a substrate 204" and a sensing material 102'" including bound multichromophores 104 disposed on at least a portion of the substrate 204", where the substrate 204" comprises a particle, according to certain embodiments.

[0192] 4, the sensing material 102''' is disposed on the surface 206 of the substrate 204'' such that the sensing material 102''' coats the surface 206 of the substrate 204''. In certain embodiments, the sensing material 102''' is chemically grafted to the surface 206 of the substrate 204''.

[0193] The particles can have any of a variety of suitable shapes. In some embodiments, the particles have a spherical shape, for example, as shown in Figure 4. In other embodiments, the particles have an angular, cylindrical, cubic, ellipsoidal, and / or fibrous morphology, etc.

[0194] The particles can have any of a variety of suitable sizes. According to certain embodiments, the particles are microparticles (e.g., particles having a maximum characteristic dimension of 1 micrometer to 100 micrometers). In certain embodiments, the particles are nanoparticles (e.g., particles having a maximum characteristic dimension of 1 nanometer to 1 micrometer).

[0195] The particles can comprise any of a variety of suitable materials. According to certain embodiments, the particles are magnetic, allowing the particles to be manipulated using a magnetic field. In certain embodiments, for example, a magnet can be used to move, collect, organize, and / or localize one or more particles. In some embodiments, a magnet can be used to remove one or more magnetic particles from a solution to which they have been added (e.g., to detect the presence of a fluoroalkyl substance in the solution, as described in more detail herein). In some embodiments, the particles comprise a metal. In certain embodiments, for example, the particles comprise iron (Fe), nickel (Ni), cobalt (Co), and / or combinations thereof. In some embodiments, the particles comprise a zeolite. In certain embodiments, the particles comprise a polymer. Other materials and / or combinations of the above materials are also possible.

[0196] According to certain embodiments, a method for detecting a fluoroalkyl substance is described. In some embodiments, the method includes exposing a bound multichromophore to a solution containing the fluoroalkyl substance. According to some embodiments, the exposing includes exposing the bound multichromophore to the fluoroalkyl substance such that the bound multichromophore absorbs the fluoroalkyl substance.

[0197] The solution can be any of a variety of suitable solutions. In some embodiments, for example, the solution is an aqueous solution. Any of a variety of suitable aqueous solutions can be used, including, but not limited to, deionized water, tap water, well water, wastewater, reservoir water, ocean water, seawater, pond water, lake water, river water, water from industrial areas, water from semiconductor manufacturing areas, water distributed to towns and / or cities, and aqueous food solutions. In other embodiments, the solution is a non-aqueous solution. In certain embodiments, for example, the solution includes an organic solvent.

[0198] The fluoroalkyl substance can be any of a variety of suitable fluoroalkyl substances, as described in more detail elsewhere herein. In some embodiments, for example, the fluoroalkyl substance is a PFAS.

[0199] According to some embodiments, the solution includes one or more non-target analytes, such as one or more metal ions, polymers, biopolymers, humic acids, and / or organic oils or surfactants. Other non-target analytes are possible.

[0200] In certain embodiments, the exposing step includes exposing a film of sensing material including bound multichromophores to a solution including a fluoroalkyl substance. Figures 5A-5B show a film of sensing material 106 including bound multichromophores 104, depicted generally as "CF x5A-5B show schematic diagrams illustrating a method including exposing a film 106 of sensing material including bound multichromophores 104 to a solution 504 including fluoroalkyl substances 506. According to certain embodiments, as shown in FIG. 5A, a film 106 of sensing material including bound multichromophores 104 is inserted into the solution 504 including fluoroalkyl substances 506. In some embodiments, as shown in FIG. 5B, after inserting the film 106 of sensing material including bound multichromophores 104 into the solution 504 including fluoroalkyl substances 506, the bound multichromophores 104 absorb the fluoroalkyl substances 506. In some embodiments, for example, when the solution 504 including fluoroalkyl substances 506 contacts the surface of the film 106 of sensing material including bound multichromophores 104, the fluoroalkyl substances 506 diffuse into the bound multichromophores 104. According to certain embodiments, as shown in FIGS. 5A-5B, the solution 504 is placed in a container 502.

[0201] 6A-6B show schematic diagrams illustrating another method that includes exposing a film 106 of sensing material including bound multichromophores 104 to a solution 504 including a fluoroalkyl substance 506, according to certain embodiments. According to certain embodiments, as shown in FIG. 6A, the solution 504 including the fluoroalkyl substance 506 is applied to the surface 206′ of the film 106 of sensing material including bound multichromophores 104. In certain embodiments, for example, the solution 504 including the fluoroalkyl substance 506 may be poured, drop-cast, and / or cast onto the surface 206′ of the film 106 of sensing material including bound multichromophores 104. In some embodiments, as shown in FIG. 6B, after the solution 504 including the fluoroalkyl substance 506 is applied to the surface 206′ of the film 106 of sensing material including bound multichromophores 104, the bound multichromophores 104 absorb the fluoroalkyl substance 506. For example, in some embodiments, when a solution 504 containing fluoroalkyl substances 506 contacts a surface 206 ′ of a film 106 of sensing material containing bound multichromophores 104 , the fluoroalkyl substances 506 diffuse into the bound multichromophores 104 .

[0202] According to certain embodiments, a film of sensing material containing bound multichromophores can be configured as a lateral flow assay architecture. In some such embodiments, when a film of sensing material containing bound multichromophores is exposed to a solution containing a fluoroalkyl substance, at least a portion of the solution containing the fluoroalkyl substance can flow along the surface of the film by capillary action. For example, with reference to Figures 6A-6B, when a film 106 of sensing material containing bound multichromophores 104 is exposed to a solution 504 containing a fluoroalkyl substance 506, at least a portion of the solution 504 containing the fluoroalkyl substance 506 can flow along the surface 206' of the film 106 by capillary action.

[0203] In some embodiments, the exposing step includes exposing a plurality of particles of a sensing material including an attached multichromophore to a solution including a fluoroalkyl substance. Figures 7A-7B show schematic diagrams depicting a method including exposing a plurality of particles 108 of a sensing material including an attached multichromophore 104 to a solution 504 including a fluoroalkyl substance 506, according to certain embodiments. According to certain embodiments, as shown in Figure 7A, a plurality of particles 108 of a sensing material including an attached multichromophore 104 are added to a solution 504 including a fluoroalkyl substance 506. In certain embodiments, as shown in Figures 7A-7B, solution 504 is placed in a container 502. According to some embodiments, one or more particles 108 have a density greater than the density of solution 504, such that one or more particles 108 sink in solution 504 (e.g., to the bottom of container 502). In certain embodiments, the one or more particles 108 have a density that is less than the density of the solution 504 such that the one or more particles 108 float on the surface 206'' of the solution 504. According to certain embodiments in which the particles are magnetic, a magnet can be used to collect, move, organize, and / or localize the magnetic particles, as described in more detail herein.

[0204] 7B, after a plurality of particles 108 of sensing material including bound multichromophores 104 are added to a solution 504 including fluoroalkyl substances 506, the bound multichromophores 104 absorb the fluoroalkyl substances 506. For example, in certain embodiments, when the solution 504 including fluoroalkyl substances 506 contacts the surface of a plurality of particles 108 of sensing material including bound multichromophores 104, the fluoroalkyl substances 506 diffuse into the bound multichromophores 104.

[0205] According to certain embodiments, the exposing step includes exposing the sensing material including the substrate and the bound multichromophore disposed on the substrate to a solution including a fluoroalkyl substance. Figures 8A-8B show schematic diagrams illustrating a method including exposing the sensing material 102' including the substrate 204 and the bound multichromophore 104 disposed on the substrate 204 to a solution 504 including a fluoroalkyl substance 506, according to certain embodiments. According to certain embodiments, as shown in Figure 8A, the sensing material 102' including the substrate 204 and the bound multichromophore 104 disposed on the substrate 204 is inserted into the solution 504 including the fluoroalkyl substance 506. In some embodiments, as shown in Figure 8B, after the sensing material 102' including the substrate 204 and the bound multichromophore 104 disposed on the substrate 204 is inserted into the solution 504 including the fluoroalkyl substance 506, the bound multichromophore 104 absorbs the fluoroalkyl substance 506. For example, in some embodiments, when a solution 504 containing fluoroalkyl substances 506 contacts the surface of a sensing material 102′ containing bound multichromophores 104, the fluoroalkyl substances 506 diffuse into the bound multichromophores 104. In one particular embodiment, the solution 504 is placed in a container 502, as shown in Figures 8A-8B.

[0206] 9A-9B show schematic diagrams depicting another method including exposing a substrate 204 and a sensing material 102′ including bound multichromophores 104 disposed on the substrate 204 to a solution 504 including a fluoroalkyl substance 506, according to certain embodiments. In some embodiments, as shown in FIG. 9A , the solution 504 including the fluoroalkyl substance 506 is applied to the surface 206′″ of the sensing material 102′ including bound multichromophores 104. In some embodiments, for example, the solution 504 including the fluoroalkyl substance 506 may be poured, drip-cast, and / or cast onto the surface 206′″ of the sensing material 102′ including bound multichromophores 104. In some embodiments, as shown in FIG. 9B , after the solution 504 including the fluoroalkyl substance 506 is applied to the surface 206′″ of the sensing material 102′ including bound multichromophores 104, the bound multichromophores 104 absorb the fluoroalkyl substance 506. In certain embodiments, for example, when a solution 504 containing fluoroalkyl substances 506 contacts a surface 206 ′″ of a sensing material 102 ′ containing bound multichromophores 104 , the fluoroalkyl substances 506 diffuse into the bound multichromophores 104 .

[0207] According to some embodiments, a sensing material including a substrate and a bound multichromophore disposed thereon can be configured as a lateral flow assay architecture. In some such embodiments, when the substrate and the sensing material including the bound multichromophore disposed thereon are exposed to a solution including a fluoroalkyl substance, at least a portion of the solution including the fluoroalkyl substance can flow along the surface of the sensing material by capillary action. For example, with reference to Figures 9A-9B, when a sensing material 102' including a substrate 204 and a bound multichromophore 104 disposed thereon is exposed to a solution 504 including a fluoroalkyl substance 506, at least a portion of the solution 504 including the fluoroalkyl substance 506 can flow along the surface 206''' of the sensing material 102' by capillary action.

[0208] 10A-10C show schematic diagrams depicting a method that includes exposing a substrate 204′ and a sensing material 102″ including bound multichromophores 104 disposed on the substrate 204′ to a solution 504 including a fluoroalkyl substance 506, according to certain embodiments, where the substrate 204′ and the sensing material 102″ include a plurality of pores 210 (e.g., pores 210a, 210b, and 210c). In some embodiments, as shown in FIG. 10A , the solution 504 including the fluoroalkyl substance 506 is applied to the surface 206′″ of the sensing material 102″ including bound multichromophores 104. In certain embodiments, for example, the solution 504 including the fluoroalkyl substance 506 may be poured, drip-cast, and / or cast onto the surface 206′″ of the sensing material 102″ including bound multichromophores 104. In some embodiments, as shown in FIG. 10B , after a solution 504 including fluoroalkyl substances 506 is added to a surface 206′″ of a sensing material 102″ including bound multichromophores 104, the bound multichromophores 104 absorb the fluoroalkyl substances 506. For example, in some embodiments, when the solution 504 including fluoroalkyl substances 506 contacts the surface 206′″ of a sensing material 102″ including bound multichromophores 104, the fluoroalkyl substances 506 diffuse into the bound multichromophores 104. According to certain embodiments, as shown in FIG. 10C , after the bound multichromophores 104 absorb the fluoroalkyl substances 506, the solution 504 may flow through one or more pores 210 (e.g., pores 210a, 210b, and / or 210c).

[0209] 11A-11B show schematic diagrams depicting a method that includes exposing a sensing material 102''' comprising a substrate 204'' and bound multichromophores 104 disposed on the substrate 204'', where the substrate 204'' comprises particles, to a solution 504 comprising a fluoroalkyl substance 506, according to certain embodiments. In certain embodiments, as shown in FIG. 11A, a plurality of substrates 204'' (e.g., particle substrates) and sensing material 102''' comprising bound multichromophores 104 disposed on the substrate 204'' are added to a solution 504 comprising a fluoroalkyl substance 506. In certain embodiments, as shown in FIGS. 11A-11B, solution 504 is placed in a container 502. In some embodiments, the sensing material 102''' including the one or more substrates 204'' (e.g., particle substrates) and the bound multichromophores 104 disposed on the one or more substrates 204'' has a density greater than that of the solution 504, such that the sensing material 102''' including the one or more substrates 204'' and the bound multichromophores 104 disposed on the one or more substrates 204'' sinks in the solution 504 (e.g., to the bottom of the container 502). In some embodiments, the sensing material 102''' including the one or more substrates 204'' (e.g., particle substrates) and the bound multichromophores 104 disposed on the one or more substrates 204'' has a density less than that of the solution 504, such that the sensing material 102''' including the one or more substrates 204'' and the bound multichromophores 104 disposed on the one or more substrates 204'' floats on the surface 206'' of the solution 504. According to certain embodiments in which the particles are magnetic, magnets can be used to collect, move, organize, and / or localize the magnetic particles, as described in more detail herein.

[0210] 11B, after a sensing material 102''' including a plurality of substrates 204'' (e.g., particle substrates) and bound multichromophores 104 disposed on the substrates 204'' is added to a solution 504 including fluoroalkyl substances 506, the bound multichromophores 104 absorb the fluoroalkyl substances 506. In certain embodiments, for example, when the solution 504 including fluoroalkyl substances 506 contacts the surface of the sensing material 102''' including bound multichromophores 104, the fluoroalkyl substances 506 diffuse into the bound multichromophores 104.

[0211] According to certain embodiments, the method includes detecting a change in the electromagnetic radiation (eg, light) emission of at least one chromophore of the bound multichromophore.

[0212] In some embodiments, the detecting step includes detecting a change in electromagnetic radiation (e.g., light) emission using a detector and / or reader. Any of a variety of detectors and / or readers can be used to detect a change in electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore. In certain embodiments, for example, the detector and / or reader is a fluorescence spectrometer, a photodiode, a photovoltaic device, a personal eye (e.g., detecting a visible colorimetric change), and / or a smartphone. Other detectors and / or readers are possible.

[0213] According to some embodiments, as described in more detail elsewhere herein, at least one chromophore exhibits a change in electromagnetic radiation (eg, light) emission in response to the presence of a fluoroalkyl substance.

[0214] In certain embodiments, at least one chromophore exhibits a change in electromagnetic radiation (e.g., light) emission in response to protonation of the attached multichromophore by a fluoroalkyl substance. According to some embodiments, for example, the attached multichromophore includes a moiety (e.g., an N-containing moiety such as a pyridine-containing moiety) that can be protonated by a fluoroalkyl substance, and the fluoroalkyl substance is a Bronsted acid. In some embodiments, the detecting step includes detecting a wavelength shift of the electromagnetic radiation emission of the at least one chromophore to a lower energy emission.

[0215] According to some embodiments, the detecting step comprises detecting a ratiometric change in electromagnetic radiation (e.g., light) emission of at least two chromophores of the linked multichromophore, wherein the at least two chromophores exhibit a ratiometric change in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance. In certain embodiments, for example, the linked multichromophore comprises a dye (e.g., a small molecule and / or polymer, such as a squaraine, oxazine, perylene bisimide, conjugates thereof, and / or combinations thereof). In some embodiments, the detecting step comprises detecting a first chromophore of the at least two chromophores that exhibits an increase in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance, and detecting a second chromophore of the at least two chromophores that exhibits a decrease in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance.

[0216] In certain embodiments, the detecting step includes determining the concentration of the fluoroalkyl substance by a change in the electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore. In certain embodiments, the change in the electromagnetic radiation emission of at least one chromophore as a function of time corresponds to the concentration of the fluoroalkyl substance being detected. In some embodiments, for example, the excited state lifetime of the change in the electromagnetic radiation emission of at least one chromophore is proportional to the concentration of the fluoroalkyl substance being detected. In certain embodiments, the ratiometric change in the electromagnetic radiation emission of at least two chromophores corresponds to the concentration of the fluoroalkyl substance being detected.

[0217] According to some embodiments, the detecting step comprises comparing a change in electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore to a reference signal. In certain embodiments, the reference signal is unresponsive to the fluoroalkyl substance.

[0218] According to certain embodiments, a system is described. Figure 12 shows a schematic diagram of a system 602 including a source 604 of solution and a sensing material 102 including bound multichromophores, as described in more detail elsewhere herein, according to certain embodiments.

[0219] Source 604 can be any of a variety of suitable sources. In certain embodiments, for example, source 604 is a well, a body of water (e.g., ocean, sea, pond, lake, river, etc.), a residential unit, a commercial unit, an industrial plant, a semiconductor manufacturing area, a water treatment plant, a water distribution area, a food manufacturing plant, etc. Other sources are possible.

[0220] The solution can be any of a variety of suitable solutions, as described in more detail elsewhere herein. In certain embodiments, for example, the solution comprises an aqueous solution (e.g., deionized water, tap water, well water, wastewater reservoir water, ocean water, seawater, pond water, lake water, river water, water from industrial areas, water from semiconductor manufacturing areas, water distributed to towns and / or cities, and aqueous food solutions, etc.). In other embodiments, the solution comprises a non-aqueous solution (e.g., the solution comprises an organic solvent).

[0221] In some embodiments, the solution comprises a fluoroalkyl substance (e.g., a PFAS, as described in more detail elsewhere herein). In certain embodiments, the solution comprises one or more non-target analytes, such as one or more metal ions, polymers, biopolymers, humic acids, and / or organic oils or surfactants. Other non-target analytes are also possible.

[0222] 12, the source 604 includes a fluid outlet 606. In some embodiments, the fluid outlet 606 is configured to allow the solution to flow from the source 604 along a direction 610 to an outlet 608 of the fluid outlet 606.

[0223] In certain embodiments, system 602 comprises a means for concentrating the fluoroalkyl material. In some embodiments, for example, system 602 comprises one or more means for heating the solution to concentrate the fluoroalkyl material in the solution.

[0224] 12 , the sensing material 102 including the bound multichromophore may be positioned along the fluid outlet 606 such that the sensing material 102 including the bound multichromophore is exposed to the solution as the solution flows from the source 604 along direction 610 to the outlet 608 of the fluid outlet 606. In some embodiments, for example, the sensing material 102 may be configured as a film or a plurality of particles. In certain embodiments, the sensing material 102 is disposed on a substrate such that the sensing material 102 disposed on the substrate is configured as a filter or membrane. In some embodiments, the sensing material 102 is disposed on a plurality of particles. In certain embodiments, the sensing material 102 is coated on the inner surface of the fluid outlet 606.

[0225] In certain embodiments, sensing material 102 including bound multichromophores is configured to detect the presence of fluoroalkyl substances in solution as the solution flows from source 604 along direction 610 to outlet 608 of fluid outlet 606, as described in more detail elsewhere herein. According to certain embodiments, system 602 comprises one or more detectors and / or readers configured to detect a change in the electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore.

[0226] In some embodiments, system 602 is configured to continuously monitor the solution for the presence of the fluoroalkyl substance. In certain embodiments, for example, system 602 may include one or more pumps and / or fans configured to continuously flow the solution from source 604 along direction 610 to outlet 608 of fluid outlet 606 such that sensing material 102 including the bound multichromophore is continuously exposed to the solution. In certain embodiments, system 602 includes one or more detectors and / or readers configured to continuously detect a change in the electromagnetic radiation (e.g., light) emission of at least one chromophore of the bound multichromophore.

[0227] U.S. Provisional Patent Application No. 63 / 385,728, filed December 1, 2022, and entitled "Detection of Fluorocarbon Compounds," is hereby incorporated by reference in its entirety for all purposes. U.S. Provisional Patent Application No. 63 / 503,979, filed May 24, 2023, and entitled "Detection of PFAS," is also hereby incorporated by reference in its entirety for all purposes.

[0228] The following examples are intended to illustrate certain embodiments of the present invention, but do not exemplify the full scope of the invention. [Example]

[0229] Example 1 Herein, we demonstrate how the self-amplifying properties of fluorescent conjugated polymers enable the detection of aqueous PFASs at ng / L levels. Signal amplification in coupled amplifying fluorescent polymer (AFP) systems is the result of highly efficient excited-state (exciton) transport along the polymer backbone and between adjacent polymers. Rapidly diffusing excitons can sample potentially thousands of polymer repeat units, increasing the probability of encountering the analyte of interest (in this case, PFAS). The exciton is trapped when the presence of the analyte triggers a lower-energy trapping state in the quenching site. The utility of AFPs has been demonstrated in a wide variety of chemical and biological sensing applications, and in some cases, these methods have proven sufficiently robust to be implemented in commercially available sensing devices.

[0230] We report a novel sensing platform based on fluorescent polymers that specifically bind and respond to PFASs in aqueous environments. This method utilizes highly fluorinated polymers of poly(p-phenyleneethynylene) (PPE) and polyfluorene (PF) motifs with pyridine-based selectors. These selectors react with acidic PFASs (i.e., PFOA and PFOS) via proton-transfer reactions (see Figure 13). Fluorinated domains within the polymer backbone partition the PFASs within the polymer, while the protonated pyridine units generate a new emission signal that is amplified by exciton energy transfer. Specifically, we designed two acidic PFAS selectors (Py and Py*, shown in Figure 13), where the π-electron delocalization feature of the thiophene bridges in Py* induces a larger fluorescence change after protonation compared to the simple pyridine selector (Py). Three different polymers (PF, PPE, and Py*, shown in Figure 13) that disrupt aggregation with respect to the polymer backbone were used. F PPE) was selected to enable spectroscopic stability and high release efficiency in thin film and particle forms. F In the case of PPE polymers, the rigid pentiptycene repeat units introduce molecular-level porosity that facilitates the diffusion of PFASs into the solid polymer.F Both PPE polymers have a particularly high fluorine content, which increases the affinity of PFAS for the polymer (see Figure 22). Results and Discussion

[0231] AFPs were synthesized by palladium-catalyzed cross-coupling polycondensation. PF-Py and PF-Py* were prepared by Suzuki polymerization between dibromide 1, diboronate 2, and a pyridine-containing dibromide (Py or Py*) (see Figure 14A). Although all monomers were soluble in toluene, Suzuki polymerization was carried out in benzotrifluoride to solubilize the resulting polymers with fluorous characteristics. In contrast, PPE polymers were synthesized by Sonogashira polymerization between diethynyl[2.2.2]-bridged bicyclic monomers 4 or 5, diiodide 3, and a pyridine-containing diiodide (Py or Py*) in benzotrifluoride / diisopropylamine (3:2) (see Figure 14B). All polymers were purified by precipitation in methanol followed by repeated washing with hot methanol, acetone, and acetonitrile. The relative molecular weights and polydispersity indices were estimated in THF solution by gel permeation chromatography (GPC) using polystyrene standards (see Figure 22). F PPE polymers are soluble only in fluorinated solvents such as benzotrifluoride and hydrofluoroethers (e.g., HFE-7500 or HFE-7200), which prevented the determination of their molecular weight by GPC. To assess their molecular weight, dynamic light scattering (DLS) in benzotrifluoride solution was used to calculate their radius of gyration. DLS analysis revealed that the average radius was 20.8 nm for PPE-Py, F For PPE-Py*, it was suggested to be 21.6 nm, which is slightly larger than the persistence length of high molecular weight PPE.

[0232] UV-Vis absorption and fluorescence spectra of AFP were collected in dilute solutions in benzotrifluoride and in spin-cast films (see Figures 15A-15F). Related photophysical data were also collected (see Figure 23). The minimal difference in absorption and fluorescence profiles between solution and thin films suggests weak interactions between the polymers, confirming that the absence of aggregation prevents self-quenching, maintaining high emission quantum yields in thin films / particles and resulting in high reproducibility of spin-cast films. While some minor aggregation was observed in the case of PF, overall, the perfluoroalkane chains extending perpendicular to the fluorene repeat units prevent tight stacking of the conjugated backbone.

[0233] The fluorescence response of polymer thin films (30–50 Å thick) to aqueous solutions of PFOA was studied by introducing the films into sealed vials (20 mL volume) containing 10 mL of different concentrations of PFOA in Milli-Q water. The mechanism of the fluorescence change is the protonation of the nitrogen atom of the Lewis base (pyridine). The proton transfer reaction is thought to occur almost instantaneously. Consequently, the most important and time-limiting factor contributing to the fluorescence response is the time required for the PFOA molecules to diffuse from the water into the fluorophilic polymer film.

[0234] All sensing experiments were performed using a 1-hour exposure time to ensure adequate diffusion of PFAS into the film. Exposure of PPE-Py films to PFOA resulted in a broadening and red-shift of the emission peak (from 451 nm to 490 nm), visually changing the film from blue to blue-green fluorescence (see Figure 16A). This red-shift is the result of PFOA-induced protonation of pyridine units, which results in an enhancement of the electron-accepting feature and lowers the energy of the charge-transfer state. As a result of the amplifying nature of exciton transfer, only a small percentage of pyridine acceptors are protonated to produce a large response. Therefore, the short-wavelength shoulder of the initial fluorescence band likely suggests some residual emission from unprotonated PPE-Py. While the PPE-Py* polymer exhibited a similar PFOA response, thiophene produced a stronger change in emission upon PFOA-induced protonation of pyridine units (see Figure 16B). In particular, the PPE-Py* film exhibited a visual change in fluorescence color from blue to green, along with a larger red-shift of the initial band from 475 nm to 535 nm. This larger shift was expected, as the thiophene-pyridine structure was expected to have a strong charge-transfer characteristic. Figures 17A-17D show the calibration curves for both polymers, which are linear between 1 ppb and 10 ppb. The limits of detection (LODs) were calculated to be 2 ppb (PPE-Py) and 1 ppb (PPE-Py*). Furthermore, we confirmed that the films were recyclable, and most of the initial fluorescence of the PPE-Py and PPE-Py* films could be recovered by rinsing with aqueous NaOH (1 M) for 10 min and air-drying.

[0235] F The PPE polymers are highly fluorinated AFPs with fluorine contents ranging from 40 wt.% to 60 wt.% (see Figure 22). Initially, as a result of higher PFAS partitioning into the more fluorous polymer film, FIt was hypothesized that PPE would exhibit higher sensitivity. A LOD of approximately 100 ppb was observed, more than two orders of magnitude lower than other PPE analogs. This significantly lower response to PFOA was due to: F Consistent with the highly hydrophobic nature of PPE, the low wettability of the polymer film likely reduces the diffusion of PFOA into the film.

[0236] Upon exposure to PFOA, the emission bands of PF-Py and PF-Py* became broader, less intense, and red-shifted. The bands shifted from 428 nm to 482 nm for PF-Py and from 487 nm to 535 nm for PF-Py* (see Figures 15C-15D). As revealed by the thin-film photographs in Figures 16A-16D, the polymer films also exhibited a detectable visual change in fluorescence color in response to PFOA. The evolution of fluorescence intensity at the initial peak maximum for PF-Py and PF-Py* upon exposure to different PFOA concentrations (calibration curve) revealed a linear range from 10 ppb to 40 ppb, with calculated LODs of 8 ppb for PF-Py and 6 ppb for PF-Py* (see Figures 17A-17D).

[0237] It is noteworthy that PF-Py / PF-Py* AFP and PPE-Py / PPE-Py* AFP have similar LODs, suggesting that PFOA diffusion into the polymer may be a limiting factor. Interestingly, the PPE-Py / PPE-Py* and PF-Py / PF-Py* films showed no fluorescence response when exposed to a simple aqueous solution of octanoic acid, thereby demonstrating that the fluorinated segments in AFP bind to PFASs. AFP-based sensor schemes utilize relatively nonspecific proton transfer reactions and may be inherently susceptible to interference from acidic and / or ionic species commonly found in groundwater. As a result, we decided to evaluate potential interference issues that may arise in complex aqueous matrices such as groundwater. In particular, well water collected from wells in Central Vermont was selected as a realistic matrix to demonstrate the robustness of the AFP-based sensor. Figures 17A–17D show PFOA calibration curves for polymer films immersed in Milli-Q water, DI water, and well water. Only small deviations were observed in the fluorescence response to PFOA, and the detection limits were the same within the error range.

[0238] We investigated whether the method for detecting PFOA could be used to detect other acidic PFASs, such as PFOS. PPE-Py* was the AFP with the lowest LOD, and its fluorescence response to PFOS was studied. As shown in Figures 18A-18B, a clear fluorescence change was observed after exposing PPE-Py* polymer films to PFOS in Milli-Q water and well water. The calibration curve revealed a linear range from 10 ppb to 40 ppb and a calculated LOD of 5 ppb. The higher LOD for PFOS (i.e., 5 ppb for PFOS and 1 ppb for PFOA) could be a result of the greater affinity of sulfates for hydration compared to carboxylates. PFOS likely behaves as a surfactant at the fluorous / water interface. PFOS organized at the interface does not protonate pyridine, leading to a decrease in the LOD.

[0239] The AFP sensing response is likely related to the diffusion of PFOA from water into the polymer film, which in turn depends on the area of ​​the polymer / water interface. Spin-cast AFP films have limited surface area, and to increase the polymer / water interface, conjugated polymer nanoparticle (CPdot) dispersions were prepared in water. CPdots have found application in imaging and chemical sensing and can be prepared by a reprecipitation method. Briefly, a dilute solution of AFP (0.01 mg mL) in THF was dissolved in 1000 ml of water. -1 , 2 mL) was quickly added to water (8 mL) under sonication. Then, the THF was evaporated under vacuum to obtain an optically transparent aqueous dispersion of CPdots that exhibited the same color as the starting THF solution. F PPE-Py and F PPE-Py* is insoluble in non-fluorinated solvents, complicating the formation of CPdots. As a result, CPdot studies focused on PPE-Py, PPE-Py*, PF-Py, and PF-Py* CPdots. The resulting CPdot dispersions were stable for over a month with no evidence of aggregation or precipitation. The morphology of the CPdots and their size were evaluated by transmission electron microscopy (TEM) and DLS (see Figures 19A-19B). TEM images showed the presence of spherical nanoparticles, which appeared to aggregate into an interconnected network. This aggregation has been previously observed for CPdots and occurs during water evaporation due to the high hydrophobicity of the fluorinated polymer. In contrast, DLS experiments did not detect any aggregation of CPdots (PDI < 0.20) and yielded unimodal size distributions with mean hydrodynamic diameters of 92 nm (PPE-Py), 83 nm (PPE-Py*), 54 nm (PF-Py), and 44 nm (PF-Py*).

[0240] The UV-Vis absorption spectra of aqueous dispersions of CPdots were broadened compared to the absorption spectra of the conjugated polymers in benzotrifluoride solution (see Figures 15A-15F). Nevertheless, the absorption spectra of PF-Py / PF-Py*CPdots were slightly blue-shifted from the solution state, consistent with an overall decrease in the conjugation length of the AFP chains. In contrast, the absorption spectra of PPE-Py / PPE-Py*CPdots showed no blue shift. CPdots also exhibited red-shifted fluorescence spectra compared to their fluorescence spectra in solution, which is very similar to the spectra obtained in thin-film form.

[0241] Fluorescence spectra of CPdots were recorded after 1 hour of incubation with various concentrations of PFOA in Milli-Q water (see Figures 20A–20D). Consistent with the thin-film sensing experiments, exposure to PFOA resulted in a broadening and red-shift of the emission peak. Furthermore, these changes in the fluorescence spectrum were accompanied by a visible change in the fluorescence color of the CPdot aqueous dispersion. These results confirmed that PFOA can diffuse into CPdots and protonate the pyridine-based selector, causing a change in fluorescence properties. Figures 20A–20D show the calibration curves for CPdots, which reveal a linear range from approximately 0.05 ppb to 1.5 ppb. The LODs were calculated to be 0.2 ppb for PPE-Py, 0.08 ppb for PPE-Py*, 0.8 ppb for PF-Py, and 0.7 ppb for PF-Py*. These values ​​are approximately one order of magnitude lower than those found in the thin-film experiments, demonstrating the effect of the larger surface area.

[0242] Additionally, the performance of CPdot was determined to be the same in Milli-Q water and well water (see Figures 21A-21D). CPdot-based AFP sensors can also detect PFOS in addition to PFOA. PPE-Py* CPdots exhibited a fluorescence response upon exposure to different concentrations of PFOS (see Figures 18A-18B). The calibration curve for this data was linear from 0.1 ppb to 1.5 ppb, yielding a calculated LOD of 0.35 ppb. As noted, the higher LOD for PFOS compared to PFOA is likely related to its different interfacial activity. conclusion

[0243] In conclusion, we developed an amplified fluorescent polymer (AFP) capable of selectively detecting aqueous PFOA and PFOS in the nanogram range. The AFP is highly fluorinated and has a poly(p-phenyleneethynylene) and polyfluorene backbone. A pyridine-based selector was integrated into the AFP, which reacts with acidic PFAS acids via a proton-transfer reaction. PFAS-induced protonation of pyridine results in the capture of lower-energy pyridinium excitons, and emission from these sites results in a red-shift in the spectrum. These AFPs were initially evaluated as spin-coated films and are capable of detecting PFAS at concentrations of approximately 1 ppb. The larger surface area of ​​nanoparticles allows for the detection of aqueous PFAS concentrations of approximately 100 ppt. It is also noteworthy that both the polymer film and CPdots are unaffected by water type, with similar responses to PFAS observed in Milli-Q water, DI water, and well water. The relatively rapid response time (approximately 1 h) combined with the low detection limit makes this sensor scheme potentially suitable for on-site PFAS detection. Example 2

[0244] Disclosed herein are materials containing perfluoroalkane groups. The perfluoroalkane segments may be linked by other groups, including oxygen, nitrogen, halide, methylene, alkene, carboxylate, and sulfate. These materials are often collectively referred to as perfluoroalkane substances, or PFAS. Two notable PFAS molecules are perfluorooctanoic acid (PFOA) and perfluorooctane sulfate (PFOS). The term analyte is often used in the context of sensing and refers to the substance being detected. PFASs are an example of an analyte.

[0245] The sensing compositions disclosed herein refer to materials whose emission characteristics change in response to exposure to PFAS analytes, and which have an affinity for the PFAS analytes, which affinity is induced by incorporating perfluoroalkane units into the sensing composition.

[0246] Disclosed herein are electronically active polymers having perfluoroalkyl groups capable of absorbing perfluoroalkane substances (PFAS) (analytes) from water, and a small molecule dye guest that produces an optical response that can be used to determine the presence or absence of these environmental contaminants. The polymers are capable of facile energy transfer, and optionally have a conjugated backbone, allowing the polymer to transfer energy to the guest molecule, resulting in emission at a wavelength longer than the polymer's own emission. The polymers can be coated onto a solid support or in particulate form. Absorption of the PFAS from water changes the emission profile of the composition, providing a signal indicative of the presence of the analyte.

[0247] The sensing material utilizes the ability of dyes to form strongly electronically coupled complexes with host polymers. Dyes are molecules capable of absorbing light in the ultraviolet and visible ranges of the electromagnetic spectrum. Dyes can be emissive and generate new emissions by binding to another chromophore material. Alternatively, the dyes can be non-emissive. In response to the presence of PFAS analytes, the dyes in this sensing composition can exhibit changes in their energy-accepting capabilities, their emission-absorption characteristics, or their interactions with other chromophores. Electronic coupling mediates energy transfer from the polymer to the dye, and electronic coupling can create new electronic states with combined characteristics of the dye and polymer. In some cases, new electronic states are described as exciton associations, and these types of emissive species are often formed between two chromophore systems with complementary electron-donating and electron-accepting characteristics. In some cases, PFAS molecular analytes enhance the interaction between the donor and acceptor chromophores through hydrogen bonding or proton-transfer interactions. In some embodiments, the acceptor chromophore contains a Brønsted base moiety that interacts with an acidic PFAS molecule, such as perfluorooctanoic acid or perfluorosulfonic acid. This responsive acceptor molecule can be a small molecule dye or a polymer. When the donor-acceptor interaction is enhanced by the PFAS, new emissions can be observed, sometimes characterized as exciton associations.

[0248] In other cases, the donor molecule may be modulated by interaction with the acidic PFAS molecule. The polymer-dye composition may exhibit emission that is a combination of both components. In some cases, this is considered exciton-association emission. If the donor dye can interact with the PFAS through hydrogen bonding or proton transfer, its donating ability may be reduced, thus altering the nature of the emission from the material.

[0249] The polymer-dye exhibits different emission characteristics in response to PFAS, which can be used to detect the presence and concentration of PFAS. The characteristics can include a change in emission intensity as a function of wavelength. In some cases, the characteristic used to detect PFAS is the ratio of different emission intensities from the polymer-dye composition. In some cases, the characteristic used to detect PFAS is a change in excited state lifetime. The longer excited state lifetime change can be used with a delayed acquisition method to detect the emission signal without the immediate fluorescence background.

[0250] The polymer-dye sensing composition can be coated onto a surface to perform optical measurements. In some cases, the surface may comprise an optical fiber, glass, an optical waveguide, plastic, paper, or a filter. The polymer-dye sensing composition can be coated onto particles. In some cases, the particles are formed solely from the polymer-dye sensing composition. In some cases, the sensing polymer-dye composition is coated onto other particles. The particles have a large surface area, and when mixed with water, they can effectively concentrate PFAS from the water into the particles. The particles can be denser or thinner than water, allowing them to float on the surface or sink to the bottom of a water-filled container after mixing has stopped. Isolating the particles at an interface can facilitate measurement of the particle's emission characteristics related to PFAS detection. The polymer-dye sensing composition can also be coated onto magnetic particles that can be localized at an interface by applying a magnetic field.

[0251] A detection mechanism for PFASs based on electron energy transfer (ET) interruption was chosen, in which a fluorescent conjugated polymer acts as a light-harvesting unit (donor) to amplify the emission from a dye (acceptor). Two mechanisms of ET are possible in thin films: Förster resonance energy transfer (FRET) and the electron exchange pathway formulated by Dexter. The former is a long-range dipole-dipole interaction that varies primarily depending on the spectral overlap between the two components, while the latter requires efficient π-π interactions between the conjugated polymer and the acceptor to allow orbital overlap and is extremely sensitive to changes in intermolecular distances of only a few angstroms. In this context, a selective sensor scheme for detecting cyclic ketones via exchange-based ET has already been described. In this case, a small binding interaction between the analyte and the dye causes a small displacement (0.5–2 Å) of the dye, which reduces π-orbital overlap and leads to quenching of emission from the dye and increased emission from the polymer.

[0252] Disclosed herein is a ratiometric and selective sensing approach for detecting PFAS in aqueous environments via interrupted exchange-based ET. This method utilizes the ability of highly fluorinated poly(p-phenylene ethynylene) to amplify the emission of embedded fluorinated fluorophores (see Figure 24). Fluorinated domains within the polymer backbone partition PFAS into the polymer, and the rigid pentiptycene repeat units introduce molecular-level porosity, which also facilitates PFAS diffusion into the solid polymer. Exposure to aqueous solutions of PFAS results in slight displacement of the dye from the polymer backbone, thereby reducing the efficiency of ET and producing a pseudo-ratiometric fluorescence response ("polymer on / dye off"). Specifically, PPE and F Two types of PPE polymers were synthesized, where FThe PPE polymer has a particularly high fluorine content (61 wt.%) compared to PPE (43 wt.%), potentially increasing the affinity of PFASs to the polymer. Regarding acceptors, three fluorinated dyes were selected: squaraine (F-Sq), oxazine (F-Ox), and perylene bisimide (F-PBI) derivatives, which are known to have negligible spectral overlap with light-harvesting polymers that undergo ET via an electron exchange mechanism.

[0253] Fluorous squaraine (F-Sq), oxazine (F-Ox), and perylene bisimide (F-FBI) were synthesized according to previously reported procedures. F PPEs were synthesized in benzotrifluoride / diisopropylamine (3:2) by palladium-catalyzed Sonogashira polymerization between a diethynyl[2.2.2]-bridged bicyclic monomer and a diiodide (see Figure 33). Both polymers were purified by precipitation in methanol followed by repeated washing with hot methanol and acetone. The average molar mass and polydispersity index were estimated in THF solution by gel permeation chromatography (GPC) using polystyrene standards. Nevertheless, F The solubility of PPE only in fluorinated solvents prevented the determination of its molar mass by GPC. Therefore, dynamic light scattering (DLS) was used to determine the molar mass. F The length distribution of PPE was estimated. DLS measurements in benzotrifluoride solution showed an average radius of gyration of 18.7 nm, which roughly corresponds to the typical persistence length of high molecular weight poly(p-phenyleneethynylene).

[0254] To optimize the sensor formulation, several weight ratios of dye (F-Sq, F-Ox, or F-PBI) were mixed with polymer (PPE or F Briefly, the required amounts of polymer and dye were weighed and dissolved in benzotrifluoride, followed by spin-casting onto clean glass substrates. The fluorescence spectra of these thin films showed that F-Ox and F-PBI were dispersed in PPE orF When dispersed in a thin film of PPE, it exhibited negligible ET (see Figures 29A-29F), while F-Sq was shown to undergo facile energy transfer with both conjugated polymers (see Figure 25A). F Given the negligible spectral overlap between PPE and F-Sq (see Figures 29A-29B), the observed ET process is more consistent with an exchange mechanism, in which electrons are exchanged from the excited polymer to the excited state of the squaraine dye, followed by rapid relaxation and subsequent emission. For this ET process, efficient π-π interactions between the embedded dye and the polymer backbone are crucial. Thus, the rigidity of the F-Sq chromophore likely ensures close packing with the polymer backbone, while the molecular shape and / or size of F-Ox and F-PBI prevent such strong π-π interactions and prevent exchange-based ET. As a result, all subsequent sensing studies have focused on mixtures containing F-Sq. It was found that a dye loading of 0.5 wt.% provided an optimal balance between the emission from the polymer and the amplification of the emission from F-Sq, while higher dye loadings exhibited a decrease in the emission from the squaraine due to aggregation (see Figure 25A).

[0255] The detection mechanism is F The technique is based on the disruption of exchange transfer (ET) between the PPE polymer and F-Sq, where adsorbed PFAS molecules swell the conjugated polymer film and interact with the fluorinated dye, disrupting the polymer-dye π-π interactions that result in exchange-based ET. Therefore, the most important time-limiting factor contributing to the fluorescence response is the time required for PFAS molecules to diffuse from water into the fluorophilic polymer film. To ensure adequate diffusion of PFAS into the polymer film, all sensing experiments were performed using a 1-hour exposure time. Exposing such thin films (30 Å to 50 Å thick) to an aqueous solution of PFOA resulted in a decrease in F-Sq emission ("dye-off") and a decrease in the PPE / F PPE release was increased ("polymer on") (see Figure 25B). FIt is noteworthy that the sensor formulation exhibited a lower fluorescence response than that of the PPE polymer, despite the higher fluorine content of the PPE polymer. F The highly hydrophobic nature of PPE and the low wettability of its films likely reduces the diffusion of PFOA molecules from water into the polymer. The detection limit was 174 ppb for the PPE / F-Sq formulation. F For PPE / F-Sq, it was calculated to be 412 ppb. Interestingly, the PPE film did not show the same fluorescence response when exposed to a simple aqueous solution of octanoic acid (see Figure 30), thereby demonstrating that the fluorinated segments within the conjugated polymer selectively bind and respond to PFOA.

[0256] The detection mechanism of the polymer sensor utilizes the adsorption of perfluorinated molecules by a highly fluorinated polymer, which causes ET disruption between the polymer backbone and the dye. Therefore, we investigated whether the PPE-based formulation could have general application for detecting other PFAS molecules, such as PFOS. As shown in Figures 26A-26B, after exposing the PPE / F-Sq film to several concentrations of PFOS, only minor deviations in the fluorescence response were observed, and the detection limits were the same within the error range (174 ppb for PFOA and 201 ppb for PFOS). Furthermore, this nonspecific ET disruption-based sensing mechanism may be susceptible to some interferences commonly found in complex aqueous matrices (e.g., groundwater). To demonstrate the robustness of the sensor, we evaluated its performance using a realistic aqueous matrix derived from a well in Central Vermont. Nevertheless, similar fluorescence responses to PFOA and PFOS were observed, demonstrating that the polymer sensor is not affected by water type (see Figures 26A-26B).

[0257] Because the most important factor affecting the sensor is the time required for PFAS to diffuse from water into the polymer film, the observed response to PFAS is likely to be highly dependent on the polymer / water interfacial area. Therefore, we decided to use a conjugated polymer nanoparticle (CPdot) dispersion in water, with the intention of increasing the polymer / water interfacial area and accelerating the partitioning of PFAS into the polymer. The CPdot aqueous dispersion was prepared by a reprecipitation method, in which a dilute THF solution (0.01 mg mL) of the polymer / dye mixture was dissolved in water. -1 , 2 mL) was quickly added to water (8 mL) under sonication, followed by evaporation of the THF under vacuum. The resulting aqueous CPdot dispersion was optically clear and stable for more than a month with no evidence of precipitation. F The preparation of CPdots was hindered by the fact that PPE polymers are soluble only in fluorinated solvents, thereby requiring water-soluble organic solvents such as THF. As a result, CPdot detection studies focused exclusively on PPE / F-Sq formulations. The average size of CPdots was determined by DLS, yielding a unimodal size distribution (PDI < 0.20) with an average hydrodynamic diameter of 88 nm (see Figure 27A). The morphology of CPdots was investigated by transmission electron microscopy (TEM) (see Figure 27B). TEM images demonstrate the presence of spherical nanoparticles that appear to aggregate to form an interconnected network. The formation of such an interconnected network has previously been observed with CPdots and is related to the high hydrophobicity of fluorinated polymers, which tend to aggregate during water evaporation.

[0258] Interestingly, the fluorescence spectrum of the PPE / F-Sq CPdot was very similar to that obtained in thin-film form (see Figure 27C). This result also demonstrates that the F-Sq acceptor readily undergoes energy transfer when colocalized with the PPE polymer CPdot, thereby demonstrating that ET also occurs within the CPdot via an electron exchange mechanism. In this case, a dye loading of 1.0 wt.% was found to provide the optimal polymer / dye emission balance. Fluorescence spectra of the CPdot were recorded after 1 hour of incubation with different concentrations of PFOA in Milli-Q water and well water. Similar to the thin-film experiments, exposure to PFOA resulted in a pseudo-ratiometric "polymer on / dye off" response that was unaffected by water type (see Figure 28A). The CPdot-based sensor can also detect PFOS in addition to PFOA (see Figure 28B). These results confirmed that PFAS molecules can diffuse into CPdot and disrupt the π-π interactions between F-Sq and PPE, disrupting their ET. The LODs were calculated to be 43 ppb for PFOA and 78 ppb for PFOS. Comparison of the LODs of the thin films and CPdots showed that the CPdot aqueous dispersions were more sensitive than the thin films, demonstrating the impact of the larger surface area of ​​the polymer sensors.

[0259] Herein, μg L in an aqueous environment -1A novel fluorescent sensing method for selectively detecting perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) at concentrations of 100 ppb and 100 ppb is disclosed. The disclosed method is based on the light-harvesting ability of poly(p-phenyleneethynylene), which amplifies the emission from an embedded dye, and the strong distance dependence of the electron exchange-based energy transfer process. Highly fluorinated polymers and dyes were designed as sensing elements to promote the partitioning of PFAS from water into the polymer. Exposure to aqueous solutions of PFAS slightly displaces the dye from the polymer backbone, reducing the energy transfer efficiency and resulting in a pseudo-ratiometric fluorescence response ("polymer on / dye off"). These polymer / dye combinations were evaluated as spin-coated films and polymer nanoparticles, which were able to selectively detect PFAS at concentrations of approximately 200 ppb and approximately 50 ppb, respectively. Both the polymer films and nanoparticles were unaffected by water type, and similar responses to PFAS were found in Milli-Q water and well water. These results demonstrate an effective sensing approach for the on-site detection of aqueous PFAS. Materials and characterization techniques

[0260] Materials: Pentiptycene diacetylene 3 and fluorinated pseudopentiptycene diacetylene 2 were prepared according to previously reported procedures. Commercially available reagents were used as received without further purification: copper(I) iodide, tetrakis(triphenylphosphine)palladium(0), anhydrous diisopropylamine, perfluorooctanoic acid, perfluorosulfonic acid (Sigma-Aldrich); (perfluorooctyl)propyl iodide, trifluorotoluene (SynQuest), dichloromethane, tetrahydrofuran, methanol, toluene, acetone, and hexane (VWR). Anhydrous toluene was purchased from Sigma-Aldrich and dried using an INERT PureSolv MD5 solvent purification system. Deuterated solvents were purchased from Cambridge Isotope Laboratories and used as received. Milli-Q water was obtained from a Barnstead Nanopure Water System (Thermo Fisher Scientific). Well water was collected from Central Vermont. The well is located at an elevation of 1,400 feet on land adjacent to the eastern boundary of the Green Mountain National Forest.

[0261] Instrumentation: ATR-FTIR spectra were obtained on a Thermo Scientific Nicolet 6700 FTIR spectrophotometer using a Ge crystal for ATR. Solution NMR experiments were performed on a Bruker Avance spectrometer using standard pulse sequences. 1 H is 400MHz, 13C was performed at 100 MHz. Chemical shifts are given in ppm relative to TMS, and the residual solvent peak was used as the internal standard. Polymer molecular weights were determined on an HP Series 1100 GPC system at room temperature in THF at 1.0 mL / min (sample concentrations of 0.5–1 mg / mL), and approximate molecular weights were estimated using polystyrene calibration standards. High-resolution mass spectra (HRMS) were obtained using a Bruker Autoflex Speed ​​matrix-assisted laser desorption / ionization time-of-flight (MALDI-TOF) spectrometer. Mass spectra were calibrated using poly(ethylene glycol) in the appropriate mass range as an external standard.

[0262] UV-Vis absorption spectra were recorded on a Cary 60 spectrophotometer and corrected for background signals using solvent-filled cuvettes for solutions and glass slides for thin films.

[0263] Fluorescence measurements were performed using a Horiba Quanta-φ fluorescence spectrophotometer using right-angle detection for solutions and front-on detection for thin films.

[0264] Dynamic light scattering (DLS) data for polymer length distribution were obtained from a Brookhaven NanoBrook Omni using polymer solutions in benzotrifluoride (0.05 mg mL -1 The size and distribution of CPdots were also obtained using an aqueous dispersion of CPdots (2.5 μg mL from Brookhaven NanoBrook Omni). -1 Measurements were taken in three consecutive 3-minute periods with no delay between scans.

[0265] Transmission electron microscope (TEM, FEI-Technai) samples were prepared using a CPdot dispersion (1.25 μg mL ) in water. -1 ) was prepared by depositing approximately 10 μL onto a 200 mesh Cu carbon film substrate (Electron Microscopy Sciences) and allowed to dry at room temperature to evaporate all water. Experimental procedure

[0266] Preparation of polymer films: Glass substrates were washed by sequential sonication in soapy water, Milli-Q water, and isopropanol, followed by UV ozone treatment. Typically, the polymer was dissolved in benzotrifluoride at a concentration of 0.5 mg mL. -1 The polymer was dissolved at a concentration of 0.001% by weight, filtered using a 0.45 μm filter, and then applied to a glass substrate. The polymer thin film was deposited on a cover glass (10 × 10 mm), spin-cast using a WS-400-6NPP / LITE spin processor (Laurell Technologies) at a spin speed of 3000 rpm for 30 seconds, and placed under vacuum overnight before use.

[0267] PFAS detection using polymer films: The fluorescence response of polymer films to PFOA or PFOS was confirmed by introducing the polymer films into sealed vials (20 mL) containing 2.5 mL of aqueous solutions of PFOA and PFOS at room temperature. Fluorescence spectra were recorded immediately after exposing the polymer films to the solutions for a set period (1 h). Fluorescence studies were performed at an excitation wavelength of 400 nm. This procedure was repeated three times with three different polymer films for each PFOA / PFOS concentration. The mean and standard deviation were used to represent each fluorescence intensity data point for each PFOA / PFOS concentration. The limit of detection (LOD) was calculated based on the standard deviation of the curve response (σ; i.e., the standard deviation of the y-intercept of the regression line) and the slope of the calibration curve (S) according to the formula: LOD = (3.3 σ) / S. σ and S values ​​were obtained from regression analysis of the calibration curve in Microsoft Excel.

[0268] Preparation of polymer nanoparticles (CPdots): Dissolve the corresponding polymer formulation in THF (HPLC grade) at 10 μg mL -1The nanoparticles were dissolved at a concentration of 2.50 μg mL. 2 mL of this solution (pre-filtered using a 0.45 μm filter) was quickly added to 8 mL of Milli-Q water while simultaneously sonicating the water. The resulting dispersion was sonicated for an additional 10 min, and then the THF was removed by evaporation on a rotary evaporator. The resulting nanoparticle dispersion (approximately 2.50 μg mL) -1 ) was clear and had a color similar to that of the polymer in the THF solution.

[0269] PFAS detection using CPdot: The fluorescence response of CPdot to PFOA or PFOS was confirmed by mixing 1.5 mL of CPdot dispersion and 1.5 mL of PFOA / PFOS aqueous solution in a sealed vial (4 mL size) at room temperature. Fluorescence spectra were recorded immediately after incubating CPdot with PFOA / PFOS for 1 hour. Fluorescence studies were performed at an excitation wavelength of 400 nm. A total of three samples were measured for each individual PFOA / PFOS concentration. The mean and standard deviation were used to represent each fluorescence intensity data point for each PFOA / PFOS concentration. The limit of detection (LOD) was calculated based on the standard deviation of the curve response (σ; i.e., the standard deviation of the y-intercept of the regression line) and the slope of the calibration curve (S) according to the formula: LOD = (3.3 σ) / S. σ and S values ​​were obtained from regression analysis of the calibration curve in Microsoft Excel.

[0270] 1:2,5-Diiodobenzene-1,4-diol (1.0 g, 2.76 mmol), 3-(perfluorooctyl)propyl iodide (3.57 g, 6.08 mmol), and potassium carbonate (0.95 g, 6.91 mmol) were stirred in acetone (25 mL). The reaction was stirred at 60° C. for 24 hours. The mixture was cooled to room temperature, poured into water, and extracted twice with ethyl acetate. The combined organic phases were washed with 10% sodium hydroxide (aq), brine, and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by silica gel flash chromatography using DCM / hexane (1:9). Yield: 83%. IR (ν, cm -1):2885, 1497, 1451, 1355, 1198, 1141, 1049. 1 H NMR (CDCl3, 400 MHz, δ, ppm): 7.18 (s, 2H), 4.03 (t, J= 5.8 Hz, 4H), 2.50-2.30 (m, 4H), 2.18-2.05 (m, 4H). 13C NMR (CDCl3, 100 MHz, δ, ppm): 152.77, 123.04, 86.36, 68.80, 28.20 (t, J= 22.4 Hz) 20.80. 19 F NMR (CDCl3, 376 MHz, δ, ppm): -80.73, -114.24, -121.63, -121.86, -122.66, -123.42, -126.06. HRMS(MALDI):C 28 H 15 F 34 I2O2[M+H] + Calculated m / z 1282.8618; measured 1282.8592.

[0271] PPE: Under an argon atmosphere, degassed diisopropylamine / toluene (2:3, 5 mL) solvent was dissolved in dialkyne 3 1 To a 25 mL Schlenk flask containing iodide 1 (40.4 mg, 0.084 mmol), diiodide 1 (107.2 mg, 0.084 mmol), copper(I) iodide (0.8 mg, 0.0042 mmol), and tetrakis(triphenylphosphine)palladium(0) (10 mg, 0.0086 mmol) was added. The flask was deoxygenated by three freeze-pump-thaw cycles and flushed with argon. The reaction mixture was stirred at 80 °C for 72 h. After cooling to room temperature, the polymer precipitated in the solvent mixture. Tetrahydrofuran (5 mL) was then added to the reaction mixture to dissolve the polymer and carefully precipitated in methanol. The solid was redissolved in THF, precipitated in methanol, and washed with hot methanol and acetone. Yield: 77%. IR (ν, cm -1 ):3023, 2970, 1739, 1502, 1460, 1366, 1204, 1230, 1145, 1023, 753, 567. 1H NMR (CDCl3, 400 MHz, δ, ppm): 7.58-7.29 (m, 4H), 7.13-6.79 (m, 4H), 6.18-5.52 (m, 2H), 4.69-4.38 (m, 2H), 2.66-2.37 (m, 4H). 19 F NMR (CDCl3, 376 MHz, δ, ppm): -80.81, -113.93, -121.64, -121.92, -122.74, -123.17, -126.15. GPC(THF, 1mL min -1 , PS standard material): Mn=79.7kDa, Mw=127.0kDa, DM=1.60.

[0272] F PPE: Under an argon atmosphere, degassed diisopropylamine / benzotrifluoride (2:3, 5 mL) solvent was added to a 25 mL Schlenk flask containing dialkyne 22 (69.6 mg, 0.042 mmol), diiodide 1 (53.6 mg, 0.042 mmol), copper(I) iodide (0.4 mg, 0.0021 mmol), and tetrakis(triphenylphosphine)palladium(0) (4.8 mg, 0.0042 mmol). The flask was deoxygenated by three freeze-pump-thaw cycles and flushed with argon. The reaction mixture was stirred at 80 °C for 72 h. After cooling to room temperature, the mixture was diluted with benzotrifluoride (5 mL) and then carefully precipitated using methanol. The solid was redissolved in benzotrifluoride, precipitated in methanol, and washed with hot methanol and acetone. Yield: 74%. IR (ν, cm) -1 ):2970, 1739, 1506, 1365, 1196, 1143, 736, 703, 657, 521. DLS (benzotrifluoride, 0.05 mg mL -1 ): Polymer length = 18.7 nm.

[0273] It should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific implementations described above. The specific implementations described above are disclosed by way of example only. While certain embodiments of the present invention have been described and illustrated herein, those skilled in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining the results and / or one or more advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will vary depending on the particular application or applications in which the teachings of the present invention are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Therefore, it should be understood that the above-described embodiments are presented by way of example only, and that within the scope of the appended claims and equivalents thereof, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods is within the scope of the invention, unless such features, systems, articles, materials, and / or methods are mutually inconsistent.

[0274] The indefinite articles "a" and "an," as used in the specification and claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0275] The phrase "and / or," as used in the specification and claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are present conjunctively in some cases and disjunctively in other cases. Other elements other than those specifically identified by the "and / or" clause, whether related to those specifically identified elements or not, may optionally be present unless expressly stated to the contrary. Thus, as a non-limiting example, a reference to "A and / or B," when used in combination with open-ended language such as "comprising," can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); and so forth.

[0276] As used herein and in the claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be interpreted as being inclusive, i.e., including at least one element, but also including more than one of several elements or a list of elements, and optionally additional unlisted items. Only terms expressly indicating the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," shall refer to the inclusion of exactly one element of several elements or a list of elements. In general, the term "or," when used herein, shall be interpreted as indicating exclusive alternatives (i.e., "one or the other, but not both") only when accompanied by terms indicating exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0277] As used in this specification and claims, the phrase "at least one" in connection with a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but does not necessarily include at least one of each and every element specifically listed in the list of elements, and does not exclude any combinations of elements in the list of elements. This definition also allows that elements other than the specifically identified elements in the list of elements to which the phrase "at least one" refers may optionally be present, whether or not related to those specifically identified elements. Thus, as a non-limiting example, "at least one of A and B" (or, alternatively, "at least one of A or B" or, alternatively, "at least one of A and / or B") can refer in one embodiment to at least one, optionally including more than one, A, and no B (and optionally including elements other than B); in another embodiment to at least one, optionally including more than one, B, and no A (and optionally including elements other than A); in yet another embodiment to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0278] In the claims and the above specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," and "holding" are to be understood to be open-ended, i.e., to mean including, but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the U.S. Patent and Trademark Office Manual of Patent Examining Procedures Section 2111.03.

Claims

1. A sensing material comprising a bound multichromophore comprising at least one chromophore that exhibits a change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the bound multichromophore is capable of energy transfer between individual sites of the bound multichromophore.

2. 10. The sensing material of claim 1, wherein said at least one chromophore exhibits a change in electromagnetic radiation emission in response to protonation of said bound multichromophore by said fluoroalkyl substance.

3. 10. The sensing material of claim 1, wherein said bound multichromophore comprises at least two chromophores that exhibit a ratiometric change in electromagnetic radiation emission in response to the presence of said fluoroalkyl substance.

4. A sensing material comprising a bound multichromophore comprising at least one chromophore that exhibits a change in electromagnetic radiation emission in response to protonation of the bound multichromophore by a fluoroalkyl substance, wherein the bound multichromophore is capable of energy transfer between individual sites of the bound multichromophore.

5. The sensing material of any one of claims 1 to 4, wherein the bound multichromophore comprises a moiety that can be protonated by the fluoroalkyl substance.

6. The sensing material of claim 5 , wherein the moiety comprises a nitrogen (N)-containing moiety.

7. The sensing material of any one of claims 1 to 6, wherein the bound multichromophore comprises a pyridine moiety.

8. The sensing material of any one of claims 1 to 7, wherein the fluoroalkyl substance is a Bronsted acid.

9. The sensing material of any one of claims 1 to 8, wherein the change in electromagnetic radiation emission of the at least one chromophore is a wavelength shift to a lower energy emission.

10. A sensing material comprising a linked multichromophore comprising at least two chromophores that exhibit a ratiometric change in electromagnetic radiation emission in response to the presence of a fluoroalkyl substance, wherein the linked multichromophore is capable of energy transfer between individual sites of the linked multichromophore.

11. The sensing material of claim 1 , 3 , or 10 , wherein the bound multichromophore comprises a dye.

12. The sensing material of claim 11 , wherein the dye comprises a small molecule and / or a polymer.

13. The sensing material of any one of claims 11 to 12, wherein the dye comprises a squaraine, an oxazine, a perylene bisimide, a conjugate thereof, and / or a combination thereof.

14. The sensing material of any one of claims 11 to 13, wherein the dye is at least partially fluorinated.

15. 15. The sensing material of any one of claims 1, 3, and 10-14, wherein a first chromophore of the at least two chromophores exhibits an increase in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance, and a second chromophore of the at least two chromophores exhibits a decrease in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance.

16. The sensing material according to any one of claims 1 to 15, wherein the fluoroalkyl substance is a perfluoroalkyl or polyfluoroalkyl substance (PFAS).

17. The sensing material of any one of claims 1 to 16, wherein the bound multichromophore comprises a polymer.

18. The sensing material of any one of claims 1 to 17, wherein the bound multichromophore comprises a conjugated polymer.

19. 19. The sensing material of any one of claims 1 to 18, wherein the bound multichromophores comprise polyarylenes, poly(arylene vinylenes), poly(thiophenes), poly(phenylenes), poly(fluorenes), poly(phenylenes), poly(arylene ethynylenes), poly(phenylene ethynylenes), copolymers thereof, and / or combinations thereof.

20. The sensing material of any one of claims 1 to 19, wherein the bound multichromophore comprises an assembly of small molecules.

21. The sensing material of any one of claims 1 to 20, wherein the bound multichromophore is at least partially fluorinated.

22. The sensing material of any one of claims 1 to 21, wherein the bound multichromophore comprises at least one fluoroalkyl group.

23. 23. The sensing material of any one of claims 21 to 22, wherein the bound multichromophores comprise fluorine in an amount equal to or greater than 25 weight percent (wt.%) based on the total weight of the bound multichromophores.

24. 24. The sensing material of any one of claims 21 to 23, wherein the bound multichromophores comprise fluorine in an amount equal to or greater than 50 wt. % based on the total weight of the bound multichromophores.

25. 25. The sensing material of any one of claims 1 to 24, wherein the sensing material is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 200 parts per billion (ppb).

26. 25. The sensing material of any one of claims 1 to 24, wherein the sensing material is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 1 ppb.

27. 25. The sensing material of any one of claims 1 to 24, wherein the sensing material is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 10 parts per trillion (ppt).

28. A sensing material according to any preceding claim, wherein the sensing material comprises a film comprising the bound multichromophores.

29. A sensing material according to any preceding claim, wherein the sensing material comprises a plurality of particles comprising the bound multichromophore.

30. The sensing material of any one of claims 1 to 29, wherein the sensing material is configured to absorb the fluoroalkyl substance.

31. The sensing material of any one of claims 1 to 30, wherein the quantum yield of the bound multichromophores is equal to or greater than 30%.

32. The sensing material of any one of claims 1 to 30, wherein the quantum yield of the bound multichromophores is equal to or greater than 70%.

33. 1. A method for detecting a fluoroalkyl substance, comprising: exposing the bound multichromophore to a solution containing said fluoroalkyl material; detecting a change in electromagnetic radiation emission of at least one chromophore of said bound multichromophore, said at least one chromophore exhibiting a change in electromagnetic radiation emission in response to the presence of said fluoroalkyl substance; A method comprising:

34. 34. The method of claim 33, wherein said at least one chromophore exhibits a change in electromagnetic radiation emission in response to protonation of said bound multichromophore by said fluoroalkyl substance.

35. 34. The method of claim 33, wherein the detecting step comprises detecting a ratiometric change in electromagnetic radiation emission of at least two chromophores of the bound multichromophore, the at least two chromophores exhibiting the ratiometric change in electromagnetic radiation emission in response to the presence of the fluoroalkyl substance.

36. 1. A method for detecting a fluoroalkyl substance, comprising: exposing the bound multichromophore to a solution containing said fluoroalkyl material; detecting a change in electromagnetic radiation emission of at least one chromophore of said bound multichromophore, said at least one chromophore exhibiting a change in electromagnetic radiation emission in response to protonation of said bound multichromophore by said fluoroalkyl substance; A method comprising:

37. 37. The method of any one of claims 33 to 36, wherein the attached multichromophore comprises a moiety that can be protonated by the fluoroalkyl substance.

38. 38. The method of claim 37, wherein the moiety comprises a nitrogen (N)-containing moiety.

39. 39. The method of any one of claims 33 to 38, wherein the attached multichromophore comprises a pyridine moiety.

40. 40. The method of any one of claims 33 to 39, wherein the fluoroalkyl material is a Bronsted acid.

41. 41. The method of any one of claims 33 to 40, wherein the detecting step comprises detecting a wavelength shift of the electromagnetic radiation emission of the at least one chromophore to a lower energy emission.

42. 1. A method for detecting a fluoroalkyl substance, comprising: exposing the bound multichromophore to a solution containing said fluoroalkyl material; detecting a ratiometric change in electromagnetic radiation emission of at least two chromophores of said bound multichromophore, said at least two chromophores exhibiting said ratiometric change in electromagnetic radiation emission in response to the presence of said fluoroalkyl substance; A method comprising:

43. 43. The method of any one of claims 33, 35, and 42, wherein the attached multichromophore comprises a dye.

44. 44. The method of claim 43, wherein the dye comprises a small molecule and / or a polymer.

45. 45. The method of any one of claims 43-44, wherein the dye comprises a squaraine, an oxazine, a perylene bisimide, a conjugate thereof, and / or a combination thereof.

46. 46. ​​The method of any one of claims 43 to 45, wherein the dye is at least partially fluorinated.

47. the detecting step detecting a first chromophore of said at least two chromophores that exhibits an increase in electromagnetic radiation emission in response to the presence of said fluoroalkyl substance; and detecting a second chromophore of said at least two chromophores that exhibits a decrease in electromagnetic radiation emissions in response to the presence of said fluoroalkyl substance; 47. The method of any one of claims 33, 35, and 42-46, comprising:

48. The method of any one of claims 33 to 47, wherein the solution is an aqueous solution.

49. 49. The method of any one of claims 33 to 48, wherein the fluoroalkyl substance is a perfluoroalkyl or polyfluoroalkyl substance (PFAS).

50. 50. The method of any one of claims 33 to 49, wherein the attached multichromophore comprises a polymer.

51. The method of any one of claims 33 to 50, wherein the attached multichromophore comprises a conjugated polymer.

52. 52. The method of any one of claims 33-51, wherein the attached multichromophore comprises polyarylene, poly(arylene vinylene), poly(thiophene), poly(phenylene), poly(fluorene), poly(phenylene), poly(arylene ethynylene), poly(phenylene ethynylene), copolymers thereof, and / or combinations thereof.

53. 53. The method of any one of claims 33 to 52, wherein the bound multichromophore comprises an assembly of small molecules.

54. 54. The method of any one of claims 33 to 53, wherein the attached multichromophore is at least partially fluorinated.

55. 55. The method of any one of claims 33 to 54, wherein the attached multichromophore comprises at least one fluoroalkyl group.

56. 56. The method of any one of claims 54 to 55, wherein the bound multichromophore comprises fluorine in an amount equal to or greater than 25 weight percent (wt.%) based on the total weight of the bound multichromophore.

57. 57. The method of any one of claims 54 to 56, wherein the bound multichromophore comprises fluorine in an amount equal to or greater than 50 wt. % based on the total weight of the bound multichromophore.

58. 58. The method of any one of claims 33 to 57, wherein the bound multichromophore is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 200 parts per billion (ppb).

59. 58. The method of any one of claims 33 to 57, wherein the bound multichromophore is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 1 ppb.

60. 58. The method of any one of claims 33 to 57, wherein the bound multichromophore is capable of detecting the presence of the fluoroalkyl substance with a sensitivity equal to or less than 10 parts per trillion (ppt).

61. 61. The method of any one of claims 33 to 60, wherein the exposing step comprises exposing a film comprising the bound multichromophore to the solution comprising the fluoroalkyl material.

62. 61. The method of any one of claims 33 to 60, wherein the exposing step comprises exposing a substrate and the bound multichromophore disposed on the substrate to the solution comprising the fluoroalkyl material.

63. 61. The method of any one of claims 33 to 60, wherein the exposing step comprises exposing a plurality of particles comprising the bound multichromophore to the solution comprising the fluoroalkyl substance.

64. 64. The method of any one of claims 33 to 63, wherein the exposing step comprises exposing the bound multichromophore to the fluoroalkyl substance such that the bound multichromophore absorbs the fluoroalkyl substance.

65. 65. The method of any one of claims 33 to 64, wherein the quantum yield of the attached multichromophore is equal to or greater than 30%.

66. 65. The method of any one of claims 33 to 64, wherein the quantum yield of the attached multichromophore is equal to or greater than 70%.

67. A method according to any one of claims 33 to 66, wherein the step of detecting comprises detecting changes in electromagnetic radiation emissions using a detector and / or reader.

68. 68. The method of claim 67, wherein the reader device is a smartphone.

69. An article comprising the sensing material of any one of claims 1 to 32.

70. 70. The article of claim 69, wherein the article is a film.

71. 71. The article of claim 70, wherein the film is a lateral flow assay architecture.

72. The article of any one of claims 69 to 71, wherein the article further comprises a substrate.

73. 73. The article of claim 72, wherein the sensing material is disposed on at least a portion of the substrate.

74. 74. The article of claim 73, wherein the sensing material coats at least a portion of the substrate.

75. The article of any one of claims 72 to 74, wherein the substrate comprises glass.

76. The article of any one of claims 72 to 74, wherein the substrate comprises a polymer.

77. The article of any one of claims 72 to 74, wherein the substrate comprises cellulose.

78. The article of any one of claims 72 to 77, wherein the substrate and / or the sensing material comprises a plurality of pores.

79. The article of any one of claims 72 to 78, wherein the article is a filter and / or a membrane.

80. The article of any one of claims 72 to 74, wherein the substrate comprises particles.

81. 81. The article of claim 80, wherein the particles are magnetic.

82. the source of the solution, and The sensing material according to any one of claims 1 to 32. Including, the system.

83. 83. The system of claim 82, wherein the solution comprises a fluoroalkyl substance.

84. 84. The system of claim 83, wherein the system is configured to continuously monitor the solution for the presence of the fluoroalkyl substance.

85. 85. The system of any one of claims 82 to 84, wherein the source is a residential unit, a commercial unit, an industrial waste plant, and / or a water treatment plant.

86. 1. A method for detecting per- and polyfluoroalkyl substances (PFAS) in an aqueous sample, comprising: providing an aqueous sample containing the PFAS; adding an amplifying fluorescent polymer (AFP) to the aqueous sample; allowing the AFP and the PFAS to form an AFP-PFAS complex; detecting the presence of the PFAS in the aqueous sample by the absorption and / or fluorescence spectra of the AFP-PFAS complex; A method comprising:

87. 87. The method of claim 86, wherein the AFP comprises a poly(p-phenylene ethynylene) backbone and / or a polyfluorene backbone.

88. The AFP may be poly(p-phenyleneethynylene) (PPE), polyfluorene (PF), and / or fluorinated poly(p-phenyleneethynylene) ( Ｆ 87. The method of claim 86, comprising a backbone moiety comprising a PPE.

89. the AFP comprises a PFAS selector; The PFAS selector has the structure: 【Chemistry 4】 and / or pyridine (Py) having the formula The PFAS selector has the structure: 【Transformation 5】 thiophene-functionalized pyridine (Py*) having the formula 87. The method of claim 86.

90. 1. A composition comprising a light-absorbing polymer and a dye, wherein the light-absorbing polymer and / or the dye comprises a perfluoroalkane group, the perfluoroalkane group comprising at least 25 w:w% fluorine, and wherein the composition produces an emission sensing signature in response to a PFAS analyte.

91. 91. The composition of claim 90, wherein the dye is a small molecule or a polymer.

92. 91. The composition of claim 90, wherein the dye is selected from fluorous squaraine (F-Sq), fluorous oxazine (F-Ox), fluorous perylene bisimide (F-FBI), and mixtures and / or conjugates thereof.

93. The light-absorbing polymer is PPE (43 w:w% fluorine) and / or Ｆ 91. The composition of claim 90, comprising a conjugated polymer comprising PPE (61 w:w% fluorine).

94. 94. The composition of any one of claims 90 to 93, wherein either or both of the light-absorbing polymer and the dye comprise a Bronsted acid.

95. 94. The composition of any one of claims 90 to 93, wherein either or both of the light-absorbing polymer and the dye comprise a Bronsted base.

96. 96. The composition of any one of claims 90-95, wherein the PFAS analyte is a Bronsted acid.

97. 97. The composition of any one of claims 90 to 96, wherein the perfluoroalkane groups contain more than 30 w:w%, 35 w:w%, 40 w:w%, or 50 w:w% fluorine.

98. The composition of any one of claims 90 to 97, wherein the light-absorbing polymer is a conjugated polymer.

99. 98. The composition of any one of claims 90-97, wherein the emission detection characteristic responsive to the PFAS analyte is a change in the ratio of two emissions.

100. 98. The composition of any one of claims 90-97, wherein the emission sensing characteristic responsive to the PFAS analyte is a change in emission intensity at a particular wavelength.

101. 98. The composition of any one of claims 90-97, wherein the emission detection signature responsive to the PFAS analyte is a change in emission intensity having a lifetime greater than 10 nanoseconds.

102. 98. The composition of any one of claims 90-97, wherein the emission detection characteristic responsive to the PFAS analyte is an increase in emission intensity.

103. 98. The composition of any one of claims 90-97, wherein the emission detection characteristic responsive to the PFAS analyte is a decrease in emission intensity.

104. 98. The composition of any one of claims 90-97, wherein the emission sensing characteristic responsive to the PFAS analyte results from the acidity of the perfluoroalkane group.

105. 98. The composition of any one of claims 90-97, wherein the emission sensing signature responsive to the PFAS analyte is derived from an exciton assembly.

106. 91. The composition of claim 90, wherein the emission sensing characteristic responsive to the PFAS analyte is detected in an aqueous solution.

107. 107. The composition of claim 106, wherein the PFAS analyte is detected at less than 200 parts per billion in the aqueous solution.

108. 108. A system comprising the composition of any one of claims 90-107, wherein said system continuously monitors water for the presence of said PFAS analyte.

109. 109. The system of claim 108, comprising a surface comprising the light-absorbing polymer and the dye.

110. 109. The system of claim 108, comprising a suspension of particles in water, said particles comprising said light-absorbing polymer and said dye.

111. 111. The system of any one of claims 108 to 110, further comprising means for concentrating the PFAS analyte.

112. 112. The system of any one of claims 108 to 111, wherein the system is capable of detecting the PFAS analyte at a concentration of less than 1 part per billion in water.

113. 112. The system of any one of claims 108 to 111, wherein the system is capable of detecting the PFAS analyte at a concentration of less than 10 parts per trillion in water.

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