Articles, systems, and methods for detection of fluoroalkyl substances

Abstract

Articles, systems, and methods for detection of fluoroalkyl substances are generally described.

Description

[0001] ARTICLES, SYSTEMS, AND METHODS FOR DETECTION OF FLUOROALKYL SUBSTANCES

[0002] RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 656,055, filed June 4, 2024, and entitled “Articles, Systems, and Methods for Detection of Fluoroalkyl Substances,” which is incorporated herein by reference in its entirety for all purposes.

[0004] TECHNICAL FIELD

[0005] Articles, systems, and methods for detection of fluoroalkyl substances are generally described.

[0006] BACKGROUND

[0007] Per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals,” are a growing concern in the sphere of human and environmental health. In response, rapid, reproducible, and inexpensive methods for PFAS detection in the environment and home water supplies are needed.

[0008] SUMMARY

[0009] Articles, systems, and methods for detection of fluoroalkyl substances are generally described. The subject matter of the present invention involves, in some cases, interrelated products, alternative solutions to a particular problem, and / or a plurality of different uses of one or more systems and / or articles.

[0010] According to some embodiments, an article configured to sense a fluoroalkyl substance is described. In certain embodiments, the article comprises a polymer support comprising fluorine at a surface of the polymer support, wherein an amount of fluorine at the surface of the polymer support is greater than or equal to 10 weight percent (wt.%) versus a total weight of the polymer support. In some embodiments the article comprises a sensing material, wherein the polymer support is at least partially functionalized with the sensing material. In certain embodiments, a method of detecting and / or determining a fluoroalkyl substance is described. In some embodiments, the method comprises exposing an article to a fluid suspected of comprising the fluoroalkyl substance. In certain embodiments, the article comprises a polymer support comprising fluorine in an amount greater than or equal to 10 weight percent (wt.%) versus a total weight of the polymer support and a sensing material, wherein the polymer support is at least partially functionalized with the sensing material. In some embodiments, the method comprises detecting a change in electromagnetic radiation emission of the sensing material.

[0011] 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 figures. In cases where the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. In the figures:

[0014] FIG. 1 shows, according to certain embodiments, a schematic cross-sectional diagram of an article comprising a polymer support at least partially functionalized with a sensing material.

[0015] FIG. 2 shows, according to certain embodiments, a schematic cross-sectional diagram of an article comprising a polymer support in the form of a tube.

[0016] FIG. 3 shows, according to certain embodiments, a schematic cross-sectional diagram of an article comprising a polymer support comprising a particle.

[0017] FIG. 4A shows, according to certain embodiments, a schematic cross-sectional diagram of an article comprising a polymer support deposited on a surface of a substrate. FIG. 4B shows, according to certain embodiments, a schematic cross-sectional schematic diagram of an article comprising a polymer support deposited on a surface of a substrate in the form of a particle.

[0018] FIG. 5 shows, according to certain embodiments, a cross-sectional schematic diagram representing a method of exposing an article to a fluid suspected of comprising an analyte.

[0019] FIG. 6 shows, according to certain embodiments, a schematic diagram representing a method of flowing a fluid suspected of comprising an analyte through a tube.

[0020] FIG. 7 shows, according to certain embodiments, an exemplary structure of a sensing material.

[0021] FIG. 8 shows, according to certain embodiments, spectra obtained at different times during the flow of water comprising PFAS through perfluoro alkoxy alkane (PFA) based tubing functionalized with the sensing material shown in FIG. 7.

[0022] FIG. 9 shows, according to certain embodiments, photographs of unfunctionalized PFA based tubing and PFA based tubing functionalized with the sensing material shown in FIG. 7 after exposure to various concentrations of PFAS showing visually detectable fluorescence.

[0023] FIGS. 10A-10C show, according to certain embodiments, PFA based tubing functionalized with various sensing materials.

[0024] FIG. 11 shows, according to certain embodiments, an exemplary structure of a PFA.

[0025] FIG. 12 shows, according to certain embodiments, a schematic representation of poly(dimethyl siloxane) based tubing functionalized with a sensing material.

[0026] FIG. 13 shows, according to certain embodiments, spectra obtained at different times during the flow of water comprising PFAS through poly(dimethyl siloxane) based tubing functionalized with a sensing material.

[0027] FIG. 14 shows, according to certain embodiments, a photograph of poly(dimethyl siloxane) based tubing functionalized with a sensing material.

[0028] FIG. 15A shows, according to certain embodiments, a schematic representation of a sensing material comprising a polymer comprising a light harvesting group and a responsive group. FIG. 15B shows, according to certain embodiments, exemplary structures of light harvesting groups.

[0029] FIG. 15C shows, according to certain embodiments, exemplary structures of responsive groups.

[0030] FIGS. 16A-16D show, according to certain embodiments, exemplary structures of polymers and / or small molecules suitable for use in a sensing material.

[0031] FIG. 17 shows, according to certain embodiments, a schematic diagram of a flow device.

[0032] FIG. 18 shows, according to certain embodiments, photographs of PFA based tubing functionalized with a sensing material before exposure to PFAS and after exposure to 5 ppb PFAS.

[0033] FIG. 19 shows, according to certain embodiments, the normalized intensity ratio of fluorescence after flowing water comprising PFAS through PFA based tubing.

[0034] FIG. 20 shows, according to certain embodiments, a non-limiting example of a sensing material comprising an amine proximate to an anthracene chromophore for PFAS sensing.

[0035] FIG. 21 shows, according to certain embodiments, a non-limiting example of a sensing material for PFAS sensing.

[0036] FIGS. 22-23 show, according to certain embodiments, non-limiting examples of sensing materials in which a phenol is liberated in the presence of a PFAS.

[0037] FIG. 24 shows, according to certain embodiments, exemplary structures of groups that can be catalytically removed by an acid.

[0038] FIG. 25 shows, according to certain embodiments, a non-limiting example of a sensing material comprising an acetal for PFAS sensing.

[0039] FIG. 26 shows, according to certain embodiments, a non-limiting example of a sensing material for PFAS sensing configured to generate a ketone in the presence of a PFAS.

[0040] FIGS. 27A-27B show, according to certain embodiments, non-limiting examples of sensing materials that bind to PFA tubing and their fluorescence after functionalizing the PFA tubing.

[0041] FIG. 27C shows, according to certain embodiments, non-limiting examples of sensing materials with fluorine weight percentages greater than or equal to 20 wt.% and less than or equal to 25 wt.% based on a total weight of the sensing material, wherein the sensing materials bind to PFA tubing.

[0042] FIG. 28A shows, according to certain embodiments, the functionalization of sensing materials on silica nanoparticles and spheres.

[0043] FIGS. 28B-28D show, according to certain embodiments, the fluorescence of sensing materials after functionalizing the silica nanoparticles and spheres.

[0044] FIG. 29A shows, according to certain embodiments, a non-limiting example of a sensor material for PFAS vapor sensing.

[0045] FIGS. 29B-29C show, according to certain embodiments, the response of a sensing material before and after exposure to trifluoroacetic acid (TFA) vapor.

[0046] FIG. 29D shows, according to certain embodiments, the response of a sensing material before and after exposure to perfluorooctanoic acid (PFOA) vapor.

[0047] FIGS. 30A-30E show, according to certain embodiments, non-limiting examples of sensing materials with various fluorine weight percentages, wherein the sensing materials bind to PFA tubing.

[0048] FIG. 30F shows, according to certain embodiments, the fluorescence of emission of the polymers shown in FIGS. 30A-30E.

[0049] FIG. 31 shows, according to certain embodiments, structures of pentiptycene diacetylene, fluorinated pseudo-pentiptycene diacetylene, fluorinated diiodobenzene, fluorinated dibromo fluorene, and fluorinated fluorene diboronic ester.

[0050] FIGS. 32A-32J show, according to certain embodiments, general procedures for monomer synthesis.

[0051] FIGS. 33A-33I show, according to certain embodiments, structures of polymer sensing materials.

[0052] FIGS. 34A-34B show, according to certain embodiments, emission spectra and a corresponding PFOA calibration curve.

[0053] FIGS. 35A-35B show, according to certain embodiments, emission spectra and a corresponding PFOS calibration curve.

[0054] FIGS. 36A-36B show, according to certain embodiments, emission spectra and a corresponding HFPO-DA (GenX) calibration curve.

[0055] FIGS. 37A-37B show, according to certain embodiments, emission spectra and the corresponding pH influence in the polymer activation. DETAILED DESCRIPTION

[0056] Compositions, articles, systems, and methods for detection of fluoroalkyl substances are generally described. In certain embodiments, for example, a sensing material that comprises at least one chromophore is described. In some embodiments, a sensing material that comprises a coupled-multichromophore is described. The coupled- multichromophore may be capable of energy transport and / or diffusion between individual sites of the coupled-multichromophore. In certain embodiments, for example, the coupled-multichromophore comprises individual sites that are linked through delocalized orbitals such that the coupled-multichromophore is capable of energy transport and / or diffusion through each individual site of the coupled-multichromophore. The sensing material comprising the coupled-multichromophore may be configured to detect the presence of an analyte, such as a fluoroalkyl species (e.g., a per- and / or polyfluoroalkyl substance). For example, in some embodiments, the coupled- multichromophore comprises at least one chromophore that displays a change in electromagnetic radiation (e.g., light) emission in response to a presence of the analyte. The change in electromagnetic radiation emission may, in some embodiments, be detected to determine the presence of the analyte. In certain embodiments, the presence of the analyte may be determined at ultra-trace levels, such as parts per billion (ppb) levels, parts per trillion (ppt) levels, or sub ppt levels.

[0057] In certain embodiments, the coupled- multichromophore comprises a moiety that is capable of being protonated by the analyte. In response to protonation of the coupled- multichromophore by the analyte, at least one chromophore of the couped- multichromophore may display the 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 an emission peak to a lower energy emission. In accordance with certain embodiments, upon detecting the change in electromagnetic radiation emission of the at least one chromophore, the presence of the analyte is detected.

[0058] According to some embodiments, the coupled-multichromophore comprises a dye. In response to the analyte changing an organization of at least a portion of the coupled-multichromophore comprising the dye, at least two chromophores of the coupled-multichromophore may display 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 coupled-multichromophore. In some embodiments, the ratiometric change in electromagnetic radiation emission comprises an increase in an emission peak of a first chromophore and a decrease of an emission peak of a second chromophore. In accordance with some embodiments, upon detecting the ratiometric change in electromagnetic radiation emission of the at least two chromophores, the presence of the analyte is detected.

[0059] According to some embodiments, an article configured to detect an analyte (e.g., a fluoroalkyl substance) is described. In certain embodiments, the article comprises a polymer support comprising fluorine at a surface of the polymer support, wherein an amount of fluorine at the surface of the polymer support is greater than or equal to 10 weight percent (wt.%) (e.g., greater than or equal to 20 wt.%, greater than or equal to 30 wt.%, etc.) versus a total weight of the polymer support. The fluorine content of the polymer support may advantageously be used to impart selectivity towards fluorinated materials such as fluorinated sensing materials and / or target analytes such as fluoroalkyl substances. In certain embodiments, a polymer support comprising a higher wt.% of fluorine provides for higher selectivity towards a fluorinated material over other potentially interfering (e.g., non-fluorinated) chemicals. According to certain embodiments, the polymer support comprises a polymer and the fluorine content of the polymer is calculated based on the structure of the polymer’s constituent repeating units. In some embodiments, the fluorine content at a surface of the polymer support is determined using spectroscopic methods that measure elemental compositions at surfaces, such as, e.g., X-ray Photoelectron Spectroscopy (XPS).

[0060] In certain embodiments, the article comprises a sensing material (e.g., comprising a coupled- multichromophore, as described in greater detail above), wherein the polymer support is at least partially functionalized with the sensing material. The sensing material may comprise fluorine in an amount greater than or equal to 10 wt.% (e.g., greater than or equal to 20 wt.%, greater than or equal to 30 wt.%) versus a total weight of the sensing material. The fluorine content of the sensing material may advantageously be used to impart selectivity towards fluorinated materials such as fluorinated polymer supports and / or target analytes such as fluoroalkyl substances. In certain embodiments, a sensing material comprising a higher wt.% of fluorine provides for higher selectivity towards a fluorinated material over other potentially interfering (e.g., non-fluorinated) chemicals. According to certain embodiments, the sensing material comprises a polymer and the fluorine content of the polymer is calculated based on the structure of the polymer’s constituent repeating units.

[0061] In certain non-limiting embodiments, the polymer support is in the form of a tube, and the sensing material is functionalized on an inner surface of the tube. The tube may be configured to flow a fluid (e.g., water) comprising the analyte (e.g., a fluoroalkyl substance) through the tube such that the article detects a presence of (and / or determines an amount of) the analyte. In other non-limiting embodiments, the polymer support is in the form of a film (e.g., a thin film), and the sensing material is functionalized on a surface of the film. A fluid comprising the analyte may be flowed in contact with the film such that the article detects a presence of (and / or determines an amount of) the analyte. In certain embodiments, the film may be translated (e.g., moved) in a sensing environment for continuous monitoring of the fluid and detection of the analyte. Such an embodiment may be advantageous even if the sensor response is irreversible in the sensing environment as the film can be translated to continuously expose fresh, unused sensing material to the fluid.

[0062] Methods of detecting an analyte (e.g., a fluoroalkyl substance) are also described herein. In some embodiments, for example, the sensing material comprising the coupled-multichromophore is exposed to a fluid suspected of comprising an analyte. In certain embodiments, the analyte, when present, is detected by detecting a change in electromagnetic radiation (e.g., light) emission of at least one chromophore of the coupled-multichromophore. In some embodiments, for example, the at least one chromophore of the coupled-multichromophore displays the change in electromagnetic radiation emission in response to a presence of the analyte.

[0063] In certain embodiments, a method of detecting (e.g., a presence of) and / or determining (e.g., an amount of, which can be zero or any positive amount) an analyte (e.g., a fluoroalkyl substance) comprises exposing an article to a fluid suspected of comprising the analyte. As described in greater detail above, the article may, in certain embodiments, comprise a polymer support comprising fluorine in an amount greater than or equal to 10 wt.% versus a total weight of the polymer support. In some embodiments, the article comprises a sensing material (e.g., comprising a coupled- multichromophore), wherein the polymer support is at least partially functionalized with the sensing material. As described above, the polymer support may, in certain embodiments, be in the form of a tube, and the sensing material may be functionalized on an inner surface of the tube. Exposing the article to the fluid may comprise flowing the fluid through the tube, in accordance with certain embodiments. In other embodiments, the polymer support is in the form a film and the sensing material is functionalized on a surface of the film. In some embodiments, exposing the article to the fluid comprises flowing the fluid over the film. In certain embodiments, the method comprises detecting a change in electromagnetic radiation emission of the sensing material. In certain embodiments, the presence of the fluoroalkyl substance is detected based on the change in electromagnetic radiation emission of the sensing material. In some embodiments, the amount of the fluoroalkyl substance is determined based on the change in electromagnetic radiation emission of the sensing material.

[0064] According to certain embodiments, the sensing material comprises a coupled- multichromophore. As used herein, the term “coupled-multichromophore” refers to a material that includes at least a first individual site and a second individual site that are coupled together, wherein the material is capable of including or hosting multiple chromophores. The term “coupled” as used herein indicates some level of interaction between the individual sites of the coupled-multichromophore that allows excited states generated in the coupled-multichromophore to move between the individual sites. In some embodiments, each individual site of the coupled-multichromophore may be coupled such that each individual site is bound (e.g., covalently or otherwise chemically bound) together. In certain embodiments, for example, the coupled- multichromophore is or comprises a conjugated polymer.

[0065] As used herein, the term “individual site” refers to a portion of a material (e.g., the coupled-multichromophore) that is larger than a single atom, which is separated by at least one other atom from a different individual site, and which defines a chromophore. In some embodiments, for example, an individual site of the coupled-multichromophore comprises one or more repeating units of a polymer, a portion of a polymer, a portion of a repeating unit of a polymer, a moiety, a portion of a moiety, a small molecule (e.g., a dye), a portion of a small molecule, and the like. In some cases, these individual sites each include sufficient atomic makeup and combination of atoms so as to perform a particular function associated with the disclosure herein (such as, e.g., absorption and / or emission of electromagnetic radiation), and each individual site is separated by sufficient atomic makeup from another individual site such that each individual site can perform its own function largely independently of the other, even if those functions are interrelated. For example, in some embodiments, one individual site may be involved in absorption of electromagnetic radiation, and another individual site is emissive in response to that absorption, with energy (e.g., exciton and / or electron) transfer occurring between the individual sites. Of course, the atomic makeup, connectivity, and proximity of one individual site relative to another individual site (e.g., a nearest neighbor individual site) can affect the molecular and electronic structure of either or both individual sites, but not so much as to negate the individual site’s function. This concept - different individual sites of a material that interact with electromagnetic radiation, and with each other, in this way - is well known and understood by those of ordinary skill in the art, although those of ordinary skill would not arrive at the arrangements of this disclosure and the arrangements as claimed, without the teachings and guidance of this disclosure.

[0066] Examples of individual sites, and energy transfer between individual sites, are provided more fully below.

[0067] As used herein, the term “chromophore” refers to a chemical group of a molecule that absorbs electromagnetic radiation (e.g., light, or other electromagnetic radiation including ultraviolet, infrared, and / or radiation extending beyond or completely outside the realm of visible, ultraviolet, or infrared) at a specific frequency or frequency profile, range, or pattern, and emits electromagnetic radiation at a specific frequency or frequency profile, range, or pattern. In some cases, the absorption and emission of electromagnetic radiation by a chemical group of a molecule imparts subtractive and / or additive color to the molecule. In some embodiments, the frequency at which the chromophore absorbs electromagnetic radiation and the frequency at which the chromophore emits electromagnetic radiation may be similar, but the frequency at which the chromophore emits electromagnetic radiation may be lower than the frequency at which the chromophore absorbs electromagnetic radiation. For example, in some embodiments, a photon absorbed by a chromophore creates an excited state that releases some energy through vibrations, solvent reorganization, and / or other processes, and the emitted photon is lower in energy. In other embodiments, the frequency at which the chromophore absorbs electromagnetic radiation and the frequency at which the chromophore emits electromagnetic radiation have larger changes in frequencies, in which case the radiation pattern or range of the absorption frequency and the emission frequency may not overlap, but are determinably different. For example, in certain embodiments wherein energy is transferred from one chromophore that normally emits at high frequency to a chromophore that emits at lower frequency, a large change in the frequency can be observed. As used herein, the term “electromagnetic radiation” is given its ordinary meaning in the art and refers to waves of an electromagnetic field that propagate through space and carry momentum and electromagnetic radiant energy, including radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. In some embodiments, the coupled-multichromophore is preferably excited by ultraviolet and / or visible light.

[0068] According to some embodiments, the coupled-multichromophore is capable of energy transport and / or diffusion between individual sites of the coupled- multichromophore. In certain embodiments, for example, the coupled- multichromophore comprises at least two individual sites (e.g., at least two chromophores) that are that are linked through an atomic structural link providing delocalized orbitals. In some embodiments, the at least two individual sites are capable of energy (e.g., exciton and / or electron) transport and / or diffusion from a first individual site (e.g., a first chromophore) of the coupled-multichromophore to a second individual site (e.g., a second chromophore) of the coupled-multichromophore coupled to the first individual site. In certain embodiments, the first individual site directly neighbors the second individual site. In some embodiments, a coupled-multichromophore that is capable of energy transport between individual sites of the coupled-multichromophore may advantageously be used to detect an analyte of interest due to the rapidly diffusing excitons and / or electrons sampling each individual site of the coupled- multichromophore. In certain embodiments, for example, the analyte of interest may interact with the coupled- multichromophore (e.g., with an individual site of the coupled- multichromophore), thereby generating a lower energy trapping state that captures the rapidly diffusing exciton and / or electron. In some embodiments, the coupled-multichromophore comprises at least one chromophore that displays a change in electromagnetic radiation (e.g., light) emission in response to a presence of the analyte. In certain embodiments, as described in greater detail herein, the analyte is a fluoroalkyl substance. In some embodiments, the analyte (e.g., fluoroalkyl substance) interacts with the coupled-multichromophore (e.g., with an individual site of the coupled-multichromophore), thereby generating the lower energy trapping state that captures the rapidly diffusing exciton and / or electron, which results in the coupled-multichromophore (e.g., an individual site of the coupled-multichromophore that has not interacted with the analyte and / or the individual site of the coupled- multichromophore that has interacted with the analyte) displaying the change in electromagnetic radiation emission.

[0069] According to some embodiments, the coupled-multichromophore comprises a polymer. For example, in certain embodiments, the coupled-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 of alternating double- and single-bonds such that overlapping p-orbitals create of a system of delocalized 7i-electrons. In certain embodiments, a coupled- multichromophore comprising a conjugated polymer may advantageously facilitate energy transport and / or diffusion between individual sites of the coupled- multichromophore. In some embodiments, as described herein in greater detail, a coupled-multichromophore comprising a conjugated polymer is an amplifying fluorescence polymer that is used in a sensor (e.g., a fluorescence sensor) to enhance the sensitivity of the sensor to an analyte (e.g., a fluoroalkyl substance).

[0070] In certain embodiments wherein the coupled-multichromophore comprises a polymer, one or more individual sites of the coupled-multichromophore comprise one or more repeating units of the polymer and / or a portion of one or more repeating units of the polymer. In some embodiments, for example, the coupled- multichromophore is capable of energy transport and / or diffusion between the one or more repeating units of the polymer and one or more other individual sites of the coupled-multichromophore (e.g., one or more other repeating units of the polymer).

[0071] According to certain embodiments, the polymer is porous. In some embodiments, the use of a coupled-multichromophore comprising a porous polymer advantageously facilitates absorption of an analyte (e.g., a fluoroalkyl substance) into the coupled-multichromophore. In certain embodiments, for example, a fluoroalkyl substance absorbs into the coupled-multichromophore comprising a porous polymer such that the fluoroalkyl substance diffuses into one or more pores of the porous polymer upon exposing the coupled-multichromophore to the fluoroalkyl substance.

[0072] According to certain embodiments, the porosity of the porous polymer can be characterized by the Brunauer-Emmett-Teller (BET) surface area of the porous polymer. The porous polymer may have any of a variety of suitable BET surface areas. In some embodiments, for example, the porous polymer has a BET surface area greater than or equal to 10 m2 / g, greater than or equal to 100 m2 / g, greater than or equal to 200 m2 / g, greater than or equal to 300 m2 / g, greater than or equal to 400 m2 / g, greater than or equal to 500 m2 / g, greater than or equal to 600 m2 / g, greater than or equal to 700 m2 / g, greater than or equal to 800 m2 / g, or greater than or equal to 900 m2 / g. In certain embodiments, the porous polymer has a BET surface area less than or equal to 1,000 m2 / g, less than or equal to 900 m2 / g, less than or equal to 800 m2 / g, less than or equal to 700 m2 / g, less than or equal to 600 m2 / g, less than or equal to 500 m2 / g, less than or equal to 400 m2 / g, less than or equal to 300 m2 / g, less than or equal to 200 m2 / g, or less than or equal to 10 m2 / g. Combinations of the above recited ranges are possible (e.g., the porous polymer has a BET surface area greater than or equal to 10 m2 / g and less than or equal to 1,000 m2 / g, the porous polymer has a BET surface area greater than or equal to 400 m2 / g and less than or equal to 600 m2 / g). Other ranges are also possible. The BET surface area of a porous polymer may be measured at 77 K by nitrogen sorption using a Micromeritics 3Flex analyzer, wherein the porous polymer samples are in powder form and degassed under high vacuum at 120 °C for at least 12 hours prior to analysis. It is also possible that a polymer can have limited porosity (< 50 m2 / g) and still absorb an analyte, as described herein in greater detail.

[0073] The coupled-multichromophore may comprise any of a variety of suitable polymers. In some embodiments, for example, the polymer comprises a statistical polymer, a block polymer, copolymers thereof, and / or combinations thereof. In certain embodiments, the polymer comprises a backbone comprising an acrylate, a styrene, a vinyl-ether, a norborene, an arylene, cellulose, an arylene ether, an arylene amine, a diene, a siloxane, an alkene, conjugates thereof, and / or combinations thereof. In certain embodiments, the chromophores of the coupled-multichromophore are pendant to the backbone of the polymer.

[0074] According to certain embodiments, the polymer is a fluorescent polymer. In some embodiments, for example, the polymer is an amplifying fluorescent polymer.

[0075] According to some embodiments, the coupled-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), copolymers thereof, and / or combinations thereof. Other polymers are also possible. In some embodiments, for example, the coupled-multichromophore comprises a poly(arylene ether), which is not conjugated, but energy can migrate within the polymer.

[0076] In certain embodiments, the coupled-multichromophore comprises an assembly of small molecules. In certain embodiments, for example, the coupled- multichromophore comprises an oil (e.g., a hydrocarbon, a siloxane, a halocarbon, a fluorocarbon), an alkane (e.g., a fluoro alkane), a cyclodextrin, a calixarene, a cavitand, a triptycene, an iptycene, a Lewis acid, a Lewis base, a Brpnstcd base, a metal ion, a macrocycle, conjugates thereof, and / or combinations thereof. Other small molecules are also possible.

[0077] The coupled-multichromophore may be loosely coupled or strongly coupled in aggregates. In the case of strongly coupled aggregates, it is preferable to have aggregates that give rise to enhanced emission intensity (more efficient emission) relative to the individual chromophores. These processes have been referred to as aggregation induced emission or the formation of J-aggregates. Aggregation induced emission refers to the aggregation rigidifying the molecules to prevent dissipation of the excited state energy through conformational dynamical processes. J-aggregates are produced when the electronic coupling increases the rate of the emission such that it competes more effectivity with other non-radiative processes.

[0078] In certain embodiments, the sensing material comprising the coupled- multichromophore is configured to absorb a fluoroalkyl substance. In some embodiments, for example, the coupled-multichromophore is at least partially fluorinated such that the fluorinated domain of the coupled-multichromophore advantageously partitions fluoroalkyl substances into the sensing material. In some embodiments, a fluoroalkyl substance diffuses into the sensing material comprising an at least partially fluorinated coupled-multichromophore upon exposing the sensing material to the fluoroalkyl substance.

[0079] In some embodiments, the coupled-multichromophore comprises at least one fluoroalkyl group. In certain embodiments wherein the coupled- multichromophore comprises a conjugated polymer, the at least one fluoroalkyl group may advantageously prevent close stacking between portions of the conjugated polymer. The at least one fluoroalkyl group of the coupled-multichromophore may comprise fluorine in any of a variety of suitable amounts. In some embodiments, for example, the at least one fluoroalkyl group of the coupled-multichromophore comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 55 wt.%, greater than or equal to 60 wt.%, greater than or equal to 65 wt.%, or greater than or equal to 70 wt.% versus a total weight of the at least one fluoroalkyl group of the coupled- multichromophore. In certain embodiments, the at least one fluoroalkyl group of the coupled-multichromophore comprises fluorine in an amount less than or equal to 75 wt.%, less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the at least one fluoroalkyl group of the coupled-multichromophore. Combinations of the above recited ranges are possible (e.g., the at least one fluoroalkyl group of the coupled-multichromophore comprises fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 75 wt.% versus a total weight of the at least one fluoroalkyl group of the coupled-multichromophore, the at least one fluoroalkyl group of the coupled-multichromophore comprises fluorine in an amount greater than or equal to 50 wt.% and less than or equal to 55 wt.% versus a total weight of the at least one fluoroalkyl group of the coupled- multichromophore). Other ranges are also possible. The coupled-multichromophore may comprise fluorine in any of a variety of suitable amounts. In some embodiments, for example, the coupled-multichromophore comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 55 wt.%, greater than or equal to 60 wt.%, greater than or equal to 65 wt.%, or greater than or equal to 70 wt.% versus a total weight of the coupled-multichromophore. In certain embodiments, the coupled- multichromophore comprises fluorine in an amount less than or equal to 75 wt.%, less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the coupled- multichromophore. Combinations of the above recited ranges are possible (e.g., the coupled-multichromophore comprises fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 75 wt.% versus a total weight of the coupled- multichromophore, the coupled-multichromophore comprises fluorine in an amount greater than or equal to 50 wt.% and less than or equal to 55 wt.% versus a total weight of the coupled- multichromophore). Other ranges are also possible.

[0080] In certain embodiments, the coupled- multichromophore comprises a moiety that is capable of being protonated by the fluoroalkyl substance. In some embodiments wherein the coupled-multichromophore comprises a moiety that is capable of being protonated by the fluoroalkyl substance, one or more individual sites of the coupled- multichromophore comprise the moiety that is capable of being protonated by the fluoroalkyl substance and / or a portion of the moiety that is capable of being protonated by the fluoroalkyl substance. In some embodiments, for example, the coupled- multichromophore is capable of energy transport and / or diffusion between the moiety that is capable of being protonated by the fluoroalkyl substance and one or more other individual sites of the coupled-multichromophore (e.g., one or more repeating units of a polymer). According to some embodiments, the moiety that is capable of being protonated by the fluoroalkyl substance is a Brpnstcd base. As used herein, the term “Brpnsted base” is given its ordinary meaning in the field of chemistry and refers to a species that is capable of accepting a proton (H+). In some embodiments, for example, the coupled- multichromophore comprises a nitrogen (N)-containing moiety that is capable of being protonated by the fluoroalkyl substance. The coupled-multichromophore may comprise any of a variety of suitable N-containing moieties. In some embodiments, for example, the coupled-multichromophore comprises a pyridine-containing moiety. In certain embodiments, the coupled-multichromophore comprises a pyridine- and a thiophenecontaining moiety (e.g., a thiophene-functionalized pyridine-containing moiety). Without wishing to be bound by theory, a coupled-multichromophore comprising a pyridine- and a thiophene-containing moiety may advantageously display larger changes (e.g., shifts) in electromagnetic radiation (e.g., light) emission (as compared to, for example, a coupled-multichromophore comprising a pyridine-containing moiety) due to the 7t-electron delocalizing character of thiophene.

[0081] According to some embodiments, the coupled-multichromophore comprises a pyridine-containing moiety having the structure:

[0082] One of ordinary skill in the art will recognize that there are a number of other moieties that are capable of being protonated, including, for example, pyrazines, amines, imines, triazines, nitrogen-containing conjugated heterocycles, and the like. In certain embodiments, for example, the coupled-multichromophore comprises an amine functional group proximate to a polycyclic aromatic hydrocarbon (e.g., anthracene). In certain embodiments, the amine functional group is capable of being protonated by the fluoroalkyl substance, thereby rendering the polycyclic aromatic hydrocarbon emissive. In some embodiments, the amine functional group is covalently bound to the polycyclic aromatic hydrocarbon. In other embodiments, the amine functional group is part of an amine-containing compound or moiety that is non-covalently associated with the polycyclic aromatic hydrocarbon.

[0083] According to certain embodiments, the interaction between the moiety that is capable of being protonated by the fluoroalkyl substance (e.g., the 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 is capable of being protonated by the fluoroalkyl substance and the fluoroalkyl substance is an ionic bond resulting from a proton transfer reaction.

[0084] In some embodiments, at least one chromophore of the coupled- multichromophore displays a change in electromagnetic radiation (e.g., light) emission in response to protonation of the coupled-multichromophore by the fluoroalkyl substance. In certain embodiments, for example, the fluoroalkyl substance interacts with an individual site of the coupled-multichromophore (e.g., the moiety that is capable of being protonated by the fluoroalkyl substance) such that the fluoroalkyl substance protonates the individual site of the coupled-multichromophore, thereby resulting in the entire coupled-multichromophore (e.g., individual sites of the coupled-multichromophore that have not interacted with the fluoroalkyl substance and the individual site of the coupled- multichromophore that has interacted with the fluoroalkyl substance) displaying the change in electromagnetic radiation emission.

[0085] In certain embodiments, the change in electromagnetic radiation (e.g., light) emission of the at least one chromophore is a wavelength shift of an emission peak to a lower energy emission. In some embodiments, for example, the emission peak shifts by greater than or equal to 10 nm, greater than or equal to 50 nm, greater than or equal to 100 nm, or greater than or equal to 150 nm to a lower energy emission. In certain embodiments, the emission peak shifts by less than or equal to 200 nm, less than or equal to 150 nm, less than or equal to 100 nm, or less than or equal to 50 nm to a lower energy emission. Combinations of the above recited ranges are possible (e.g., the emission peak shifts by greater than or equal to 10 nm and less than or equal to 200 nm to a lower energy emission, the emission peak shifts by greater than or equal to 50 nm and less than or equal to 100 nm to a lower energy emission). Other ranges are also possible. According to certain embodiments, the change in electromagnetic radiation (e.g., light) emission in response to protonation of the coupled-multichromophore by the fluoroalkyl substance may be an at least partially ratiometric change. In certain embodiments, for example, the change in electromagnetic radiation of the emission peak and the generation of a lower energy emission peak may be at least partially ratiometric.

[0086] In certain embodiments, the coupled-multichromophore comprises a dye. As used herein, the term “dye” is given its ordinary meaning in the art and refers to a molecule that is capable of absorbing electromagnetic radiation in the ultra-violet and / or visible range of the electromagnetic spectrum. In certain embodiments wherein the coupled-multichromophore comprises a dye, one or more individual sites of the coupled- multichromophore comprise the dye. In some embodiments, for example, the coupled- multichromophore is capable of energy transport and / or diffusion between the dye and one or more other individual sites of the coupled-multichromophore (e.g., one or more repeating units of a polymer).

[0087] The coupled-multichromophore may comprise any of a variety of suitable dyes. In certain embodiments, the dye is capable of accepting energy from one or more individual sites of the coupled-multichromophore. In some embodiments, for example, the dye comprises a small molecule and / or a polymer. In certain embodiments, the dye comprises squaraine, oxazine, perylene bisimide, coumarin, fluorocene, rodamine, cyanine, conjugates thereof, and / or combinations thereof. Other dyes are also possible.

[0088] According to some embodiments, the dye is at least partially fluorinated. In certain embodiments, the fluorinated domain of the dye advantageously partitions fluoroalkyl substances into the sensing material comprising the coupled- multichromophore. For example, in some embodiments, a fluoroalkyl substance diffuses into the coupled-multichromophore comprising an at least partially fluorinated dye upon exposing the coupled-multichromophore to the fluoroalkyl substance.

[0089] In some embodiments, the dye comprises at least one fluoroalkyl group. The at least one fluoroalkyl group of the dye may comprise fluorine in any of a variety of suitable amounts. In some embodiments, for example, the at least one fluoroalkyl group of the dye comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 55 wt.%, greater than or equal to 60 wt.%, greater than or equal to 65 wt.%, or greater than or equal to 70 wt.% versus a total weight of the at least one fluoroalkyl group of the dye. In certain embodiments, the at least one fluoroalkyl group of the dye comprises fluorine in an amount less than or equal to 75 wt.%, less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, or less than or equal to 20 wt.% versus a total weight of the at least one fluoroalkyl group of the dye. Combinations of the above recited ranges are possible (e.g., the at least one fluoroalkyl group of the dye comprises fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 75 wt.% versus a total weight of the at least one fluoroalkyl group of the dye, the at least one fluoroalkyl group of the dye comprises fluorine in an amount greater than or equal to 50 wt.% and less than or equal to 55 wt.% versus a total weight of the at least one fluoroalkyl group of the dye). Other ranges are also possible.

[0090] The dye may comprise fluorine in any of a variety of suitable amounts. In some embodiments, for example, the dye comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 35 wt.%, greater than or equal to 40 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 55 wt.%, greater than or equal to 60 wt.%, greater than or equal to 65 wt.%, or greater than or equal to 70 wt.% versus a total weight of the dye. In certain embodiments, the dye comprises fluorine in an amount less than or equal to 75 wt.%, less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the dye. Combinations of the above recited ranges are possible (e.g., the dye comprises fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 75 wt.% versus a total weight of the dye, the dye comprises fluorine in an amount greater than or equal to 50 wt.% and less than or equal to 55 wt.% versus a total weight of the dye). Other ranges are also possible.

[0091] The coupled-multichromophore may comprise the dye in any of a variety of suitable amounts. In some embodiments, for example, the coupled-multichromophore comprises the dye in an amount greater than or equal to 0.1 wt.%, greater than or equal to 0.2 wt.%, greater than or equal to 0.3 wt.%, greater than or equal to 0.4 wt.%, greater than or equal to 1 wt.%, greater than or equal to 2 wt.%, greater than or equal to 3 wt.%, or greater than or equal to 4 wt.% versus a total weight of the coupled- multichromophore. In some embodiments, the coupled-multichromophore comprises the dye in an amount less than or equal to 5 wt.%, less than or equal to 4 wt.%, less than or equal to 3 wt.%, less than or equal to 2 wt.%, less than or equal to 1 wt.%, less than or equal to 0.5 wt.%, less than or equal to 0.4 wt.%, less than or equal to 0.3 wt.%, or less than or equal to 0.2 wt.% versus a total weight of the coupled-multichromophore. Combinations of the above recited ranges are possible (e.g., the coupled- multichromophore comprises the dye in an amount greater than or equal to 0.1 wt.% and less than or equal to 5 wt.% versus a total weight of the coupled-multichromophore, the coupled-multichromophore comprises the dye in an amount greater than or equal to 0.3 wt.% and less than or equal to 0.5 wt.% versus a total weight of the coupled- multichromophore). Other ranges are also possible.

[0092] According to some embodiments, the coupled-multichromophore comprises at least two chromophores that display a ratiometric change in electromagnetic radiation (e.g., light) emission in response to a presence of a fluoroalkyl substance. As used herein, the term “ratiometric” refers to the use of a ratio of intensities of two or more emission frequencies to provide information. In some embodiments, the ratio provides greater accuracy in the detection of an analyte than the individual emission intensities can provide as a singular signal. In certain embodiments, the ratio can provide information about the amount or concentration of an analyte.

[0093] In certain embodiments, the fluoroalkyl substance may interact with the coupled- multichromophore and change an organization of at least a portion of the coupled- multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the coupled-multichromophore and triggers an electron transfer interruption between one or more individual sites of the coupled- multichromophore and the dye, resulting in the at least two chromophores of the coupled-multichromophore displaying the ratiometric change in electromagnetic radiation emission. In some embodiments, the displacement is small and the dye is not physically removed from a matrix containing the coupled-multichromophore, but is displaced such that the orbital overlap between the dye and a chromophore of the coupled-multichromophore is reduced.

[0094] According to some embodiments, a first chromophore of the at least two chromophores may be capable of donating energy to a second chromophore of the at least two chromophores. Without wishing to be bound by theory, in certain embodiments wherein the coupled-multichromophore comprises a polymer and a dye, the polymer may act as a light-harvesting unit (e.g., a donor), which supplies energy to the dye (e.g., an acceptor) and amplifies a light emission from the dye. In certain embodiments, the polymer and the dye may have no or negligible spectral overlap.

[0095] In some embodiments, a first chromophore of the at least two chromophores displays an increase in electromagnetic radiation (e.g., light) emission in response to the presence of the fluoroalkyl substance. In certain embodiments wherein the coupled- multichromophore comprises a polymer and a dye, for example, a first chromophore corresponding to the polymer (e.g., corresponding to one or more repeating units of the polymer) displays an increase in electromagnetic radiation emission in response to the fluoroalkyl substance interacting with the coupled-multichromophore and changing an organization of at least a portion of the coupled-multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the coupled-multichromophore, which triggers an electron transfer interruption between the polymer (e.g., one or more repeating units of the polymer) and the dye.

[0096] The lifetime of the increase in electromagnetic radiation (e.g., light) emission of the first chromophore may 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 greater than or equal to 1 microsecond, greater than or equal to 2 microseconds, greater than or equal to 5 microseconds, greater than or equal to 10 microseconds, greater than or equal to 20 microseconds, greater than or equal to 50 microseconds, greater than or equal to 100 microseconds, or greater than or equal to 500 microseconds. In certain embodiments, the lifetime of the increase in electromagnetic radiation emission of the first chromophore is less than or equal to 1 millisecond, less than or equal to 500 microseconds, less than or equal to 100 microseconds, less than or equal to 50 microseconds, less than or equal to 20 microseconds, less than or equal to 10 microseconds, less than or equal to 5 microseconds, or less than or equal to 2 microseconds. Combinations of the above recited ranges are possible (e.g., the lifetime of the increase in electromagnetic radiation emission of the first chromophore is greater than or equal to 1 microsecond and less than or equal to 1 millisecond, the lifetime of the increase in electromagnetic radiation emission of the first chromophore is greater than or equal to 50 microseconds and less than or equal to 200 microseconds). Other ranges are also possible, including those over 1 millisecond, are also possible.

[0097] According to certain embodiments, a second chromophore of the at least two chromophores displays a decrease in electromagnetic radiation (e.g., light) emission in response to the presence of the fluoroalkyl substance. In certain embodiments wherein the coupled-multichromophore comprises a polymer and a dye, for example, a second chromophore corresponding to the dye displays a decrease in electromagnetic radiation emission in response to the fluoroalkyl substance interacting with at least a portion of the coupled-multichromophore and changing an organization of the coupled- multichromophore. In some embodiments, for example, the fluoroalkyl substance displaces at least a portion of the dye from the coupled-multichromophore, which triggers the electron transfer interruption between the polymer (e.g., one or more repeating units of the polymer) and the dye.

[0098] The lifetime of the decrease in electromagnetic radiation (e.g., light) emission of the second chromophore may be any of a variety of suitable values. In some embodiments, for example, the lifetime of the decrease in electromagnetic radiation emission of the second chromophore is greater than or equal to 1 nanosecond, greater than or equal to 2 nanoseconds, greater than or equal to 5 nanoseconds, greater than or equal to 10 nanoseconds, greater than or equal to 20 nanoseconds, greater than or equal to 50 nanoseconds, greater than or equal to 100 nanoseconds, or greater than or equal to 500 nanoseconds. In certain embodiments, the lifetime of the decrease in electromagnetic radiation emission of the second chromophore is less than or equal to 1 microsecond, less than or equal to 500 nanoseconds, less than or equal to 100 nanoseconds, less than or equal to 50 nanoseconds, less than or equal to 20 nanoseconds, less than or equal to 10 nanoseconds, less than or equal to 5 nanoseconds, or less than or equal to 2 nanoseconds. Combinations of the above recited ranges are possible (e.g., the lifetime of the decrease in electromagnetic radiation emission of the second chromophore is greater than or equal to 1 nanosecond and less than or equal to 1 millisecond, the lifetime of the decrease in electromagnetic radiation emission of the second chromophore is greater than or equal to 50 nanoseconds and less than or equal to 200 nanoseconds). Other ranges are also possible, including those over 1 millisecond, are also possible.

[0099] The coupled-multichromophore may have any of a variety of suitable weightaverage molecular weights (Mw). In certain embodiments, for example, the coupled- multichromophore is a molecular and / or polymeric assembly having a weight-average molecular weight greater than or equal to 500 g / mol, greater than or equal to 1,000 g / mol, greater than or equal to 5,000 g / mol, greater than or equal to 10,000 g / mol, greater than or equal to 50,000 g / mol, greater than or equal to 100,000 g / mol, greater than or equal to 500,000 g / mol, greater than or equal to 1,000,000 g / mol, or greater than or equal to 1,500,000 g / mol. In some embodiments, the coupled-multichromophore is a molecular and / or polymeric assembly having a weight- average molecular weight less than or equal to 2,000,000 g / mol, less than or equal to 1,500,000 g / mol, less than or equal to 1,000,000 g / mol, less than or equal to 500,000 g / mol, less than or equal to 100,000 g / mol, less than or equal to 50,000 g / mol, less than or equal to 10,000 g / mol, less than or equal to 5,000 g / mol, or less than or equal to 1,000 g / mol. Combinations of the above recited ranges are possible (e.g., the coupled-multichromophore has a weightaverage molecular weight greater than or equal to 500 g / mol and less than or equal to 2,000,000 g / mol, the coupled-multichromophore has a weight- average molecular weight greater than or equal to 50,000 g / mol and less than or equal to 100,000 g / mol). Other ranges are also possible. The weight-average molecular weight of the coupled- multichromophore may be determined by gel permeation chromatography.

[0100] The coupled-multichromophore may have any of a variety of suitable numberaverage molecular weights (Mn). In certain embodiments, for example, the coupled- multichromophore has a number-average molecular weight greater than or equal to 500 g / mol, greater than or equal to 1,000 g / mol, greater than or equal to 5,000 g / mol, greater than or equal to 10,000 g / mol, greater than or equal to 50,000 g / mol, greater than or equal to 100,000 g / mol, or greater than or equal to 500,000 g / mol. In some embodiments, the coupled-multichromophore has a number- average molecular weight less than or equal to 1,000,000 g / mol, less than or equal to 500,000 g / mol, less than or equal to 100,000 g / mol, less than or equal to 50,000 g / mol, less than or equal to 10,000 g / mol, less than or equal to 5,000 g / mol, or less than or equal to 1,000 g / mol.

[0101] Combinations of the above recited ranges are possible (e.g., the coupled- multichromophore has a number-average molecular weight greater than or equal to 500 g / mol and less than or equal to 1,000,000 g / mol, the coupled-multichromophore has a number- average molecular weight greater than or equal to 50,000 g / mol and less than or equal to 100,000 g / mol). Other ranges are also possible. The number-average molecular weight of the coupled-multichromophore may be determined by gel permeation chromatography .

[0102] The coupled-multichromophore may have any of a variety of suitable polydispersity indices. In certain embodiments, for example, the coupled- multichromophore has a poly dispersity index greater than or equal to 1, greater than or equal to 1.5, greater than or equal to 2, or greater than or equal to 2.5. In some embodiments, the coupled-multichromophore has polydispersity index less than or equal to 3, less than or equal to 2.5, less than or equal to 2, or less than or equal to 1.5.

[0103] Combinations of the above recited ranges are possible (e.g., the coupled- multichromophore has a poly dispersity index greater than or equal to 1 and less than or equal to 3, the coupled- multichromophore has a poly dispersity index greater than or equal to 2 and less than or equal to 2.5). Other ranges are also possible. The polydispersity index of the coupled-multichromophore may be determined by dividing the weight- average molecular weight of the coupled-multichromophore by the numberaverage molecular weight of the coupled-multichromophore.

[0104] The coupled-multichromophore may 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 a ratio of the number of photons emitted by the coupled-multichromophore to the number of photons absorbed by the coupled-multichromophore. The precent quantum yield of the coupled-multichromophore may be determined according to equation 1 (eq. 1) shown below. 100 (eq. 1) In certain embodiments, the quantum yield of the coupled- multichromophore is advantageously high such that the coupled-multichromophore has a long-excited state lifetime and a low non-radiative rate. According to certain embodiments, the coupled- multichromophore has a quantum yield greater than or equal to 30%, greater than or equal to 35%, greater than or equal to 40%, greater than or equal to 45%, greater than or equal to 50%, greater than or equal to 55%, greater than or equal to 60%, greater than or equal to 65% or greater than or equal to 70%. In some embodiments, the coupled- multichromophore has a quantum yield less than or equal to 75%, less than or equal to 70%, less than or equal to 65%, less than or equal to 60%, less than or equal to 55%, less than or equal to 50%, less than or equal to 45%, less than or equal to 40%, or less than or equal to 35%. Combinations of the above recited ranges are possible (e.g., the coupled- multichromophore has a quantum yield greater than or equal to 30% and less than or equal to 75%, the coupled- multichromophore has a quantum yield greater than or equal to 50% and less than or equal to 55%). Other ranges are also possible.

[0105] According to certain embodiments, the quantum yield of the coupled- multichromophore may change upon exposure to a fluoroalkyl substance. In some embodiments, for example, the quantum yield of the coupled-multichromophore decreases upon exposure to the fluoroalkyl substance. In other embodiments, the quantum yield of the coupled-multichromophore increases upon exposure to the fluoroalkyl substance.

[0106] The coupled-multichromophore may be synthesized by methods known to a person or ordinary skill in the art. In certain embodiments, for example, the coupled- multichromophore may be synthesized by one or more polymerization reactions (e.g., Suzuki polymerization, Sonogashira polymerization, free radical polymerization, cationic polymerization, metal catalyzed polymerization, ring opening polymerization, and / or condensation polymerization) of one or more monomers.

[0107] According to some embodiments, an article configured to sense an analyte (e.g., a fluoroalkyl substance) is described. FIG. 1 shows a schematic cross-sectional diagram of article 102a. In certain embodiments, the article comprises a sensing material (e.g., comprising at least one chromophore, comprising a coupled-multichromophore, as described herein in greater detail). For example, referring to FIG. 1, article 102a comprises sensing material 104. In certain embodiments, the sensing material (e.g., sensing material 104) comprises at least one chromophore (or a coupled-multichromophore) that displays a change in electromagnetic radiation emission in response to a presence of the fluoroalkyl substance, as described herein in greater detail. In some embodiments, the sensing material comprises at least one chromophore configured to emit electromagnetic radiation. In some embodiments, the electromagnetic radiation of the at least one chromophore is emitted in the presence of a fluoroalkyl substance. In other embodiments, the electromagnetic radiation of the at least one chromophore is quenched in the presence of a fluoroalkyl substance.

[0108] In some embodiments, the sensing material comprises a nitrogen-containing heterocycle that is configured to interact with the fluoroalkyl substance such that the at least one chromophore (or the coupled-multichromophore) displays the change in electromagnetic radiation emission. The fluoroalkyl substance may, in some embodiments, be configured to protonate the nitrogen-containing heterocycle.

[0109] In certain embodiments, the sensing material comprises a dye. The fluoroalkyl substance may, in some embodiments, be configured to displace at least a portion of the dye from the sensing material such that at least two chromophores of the coupled- multichromophore display a ratiometric change in electromagnetic radiation emission. In some embodiments, the presence of the fluoroalkyl substance changes an efficiency of an energy transfer of the at least one chromophore (or the coupled- multichromophore).

[0110] According to some embodiments, the sensing material comprises at least one chromophore that displays a change in electromagnetic radiation emission in response to hydrolysis of at least a portion of the sensing material by the fluoroalkyl substance. In certain embodiments, the hydrolysis is performed in the presence of water and / or an acid. The portion of the sensing material hydrolyzed by the fluoroalkyl substance may be any of a variety of suitable moieties. In some embodiments, for example, the portion of the molecule hydrolyzed by the fluoroalkyl substance comprises a tert-butyloxycarbonyl group, an acetal group, an imine group, a vinyl ether group, an ester group, an oxygensilicon bond, and / or combinations thereof. Other functional groups and hydrolysis and / or Brpnstcd acid catalyzed reaction mechanisms are also possible.

[0111] In some embodiments, the sensing material (e.g., sensing material 104) is a fluorescent material. For example, in certain embodiments, the sensing material is a fluorescent material having a quantum yield as described herein in greater detail with respect to the coupled-multichromophore and eq. 1. In some embodiments, for example, the sensing material has a quantum yield greater than or equal to 30% and less than or equal to 75%.

[0112] In certain embodiments, the sensing material (e.g., sensing material 104) is configured to absorb an analyte (e.g., a perfluoroalkyl substance). For example, in some embodiments, the sensing material is at least partially fluorinated such that the fluorinated domain of the sensing material advantageously partitions fluoroalkyl substances into the sensing material. In some embodiments, a fluoroalkyl substance diffuses into an at least partially fluorinated sensing material upon exposing the sensing material to the fluoroalkyl substance.

[0113] In some embodiments, the sensing material (e.g., sensing material 104) is at least partially fluorous. In certain embodiments, an at least partially fluorous sensing material may advantageously have an affinity for other materials having fluorous characteristics, including, for example, a fluorinated polymer support and / or fluorinated analytes such as fluoroalkyl substances. In certain embodiments, the sensing material may be configured to bind, absorb, and / or absorb into fluorinated materials. In some embodiments, the suitability of a sensing material to bind, absorb, and / or absorb into fluorinated materials may be identified by optical absorption and / or emission spectroscopy. In some embodiments, the sensing material is configured to bind, absorb, and / or absorb into a fluorinated material (e.g., a polymer support) having a wt.% of fluorine based on a total weight of the fluorinated material that is similar to and / or higher than a wt.% of fluorine in the sensing material based on total weight of the sensing material.

[0114] According to some embodiments, the sensing material (e.g., sensing material 104) comprises fluorine in any of a variety of suitable amounts. In certain embodiments, for example, the sensing material comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 45 wt.%, greater than or equal to 50 wt.%, greater than or equal to 60 wt.%, greater than or equal to 70 wt.%, greater than or equal to 80 wt.%, or greater than or equal to 90 wt.% versus a total weight of the sensing material. In certain embodiments, the sensing material comprises fluorine in an amount less than or equal to 99 wt.%, less than or equal to 90 wt.%, less than or equal to 80 wt.%, less than or equal to 70 wt.%, less than or equal to 60 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the sensing material. Combinations of the above recited ranges are possible (e.g., the sensing material comprise fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 99 wt.% versus a total weight of the sensing material). Other ranges are also possible. The weight percent of fluorine in a sensing material comprising a polymer may be calculated using the chemical formula of the repeating unit of the polymer and the molecular weight of the repeating unit of the polymer according to equation 2 (eq. 2) shown below:

[0115] F wt. %

[0116] Atomic mass F x Number of F atoms in chemical formula x 100 (eq. 2)

[0117] MW of repeating unit

[0118] According to some embodiments, the sensing material (e.g., sensing material 104) is at least partially porous. In some embodiments, for example, the sensing material comprises a plurality of pores. The plurality of pores may have any of a variety of suitable maximum characteristic dimensions (e.g., greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 10 nm, greater than or equal to 50 nm, greater than or equal to 100 nm, greater than or equal to 500 nm, or greater).

[0119] In some embodiments, the porosity of a sensing material comprising a polymer is derived from the structure of the polymer. For example, in some embodiments, the sensing material comprises a polymer of intrinsic porosity comprising polymer chains that do not pack tightly because of three-dimensional free volume generating elements in the backbone of the polymer. The polymer may, in certain embodiments, comprise a plurality of pores having a maximum characteristic dimension from 1-2 nm to hundreds of nm. According to some embodiments, the sensing material comprises a polymer that is processed to be at least partially porous such that the polymer is a polymer of extrinsic porosity. Suitable processing methods include, for example, phase inversion wherein a film (e.g., thin film) of the polymer is immersed in a non-solvent to cause rapid solidification, which produces a plurality of pores having a maximum characteristic dimension greater than or equal to 100 nm, greater than or equal to 500 nm, or greater. In some embodiments, the sensing material comprises a polymer of both intrinsic and extrinsic porosity.

[0120] The sensing material (e.g., sensing material 104) may have any of a variety of suitable sensitivities. In certain embodiments, the sensing material is capable of detecting the presence of an analyte (e.g., a fluoroalkyl substance) at a parts per million (ppm) level. In some embodiments, for example, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppm, less than or equal to 100 ppm, or less than or equal to 10 ppm. In certain embodiments, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity greater than or equal to 1 ppm, greater than or equal to 10 ppm, or greater than or equal to 100 ppm. Combinations of the above recited ranges are possible (e.g., the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppm and greater than or equal to 1 ppm, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 100 ppm and greater than or equal to 10 ppm). Other ranges are also possible.

[0121] In some embodiments, the sensing material (e.g., sensing material 104) is capable of detecting the presence of an analyte (e.g., a fluoroalkyl substance) at a parts per billion (ppb) level. In some embodiments, for example, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppb, less than or equal to 900 ppb, less than or equal to 800 ppb, less than or equal to 700 ppb, less than or equal to 600 ppb, less than or equal to 500 ppb, less than or equal to 400 ppb, less than or equal to 300 ppb, less than or equal to 200 ppb, less than or equal to 100 ppb, less than or equal to 50 ppb, or less than or equal to 10 ppb. In certain embodiments, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity greater than or equal to 1 ppb, greater than or equal to 10 ppb, greater than or equal to 50 ppb, greater than or equal to 100 ppb, greater than or equal to 200 ppb, greater than or equal to 300 ppb, greater than or equal to 400 ppb, greater than or equal to 500 ppb, greater than or equal to 600 ppb, greater than or equal to 700 ppb, greater than or equal to 800 ppb, or greater than or equal to 900 ppb. Combinations of the above recited ranges are possible (e.g., the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppb and greater than or equal to 1 ppb, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 500 ppb and greater than or equal to 400 ppb). Other ranges are also possible.

[0122] According to certain embodiments, the sensing material (e.g., sensing material 104) is capable of detecting the presence of an analyte (e.g., a fluoroalkyl substance) at a parts per trillion (ppt) level. In some embodiments, for example, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppt, less than or equal to 900 ppt, less than or equal to 800 ppt, less than or equal to 700 ppt, less than or equal to 600 ppt, less than or equal to 500 ppt, less than or equal to 400 ppt, less than or equal to 300 ppt, less than or equal to 200 ppt, less than or equal to 100 ppt, less than or equal to 50 ppt, or less than or equal to 10 ppt. In certain embodiments, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity greater than or equal to 1 ppt, greater than or equal to 10 ppt, greater than or equal to 50 ppt, greater than or equal to 100 ppt, greater than or equal to 200 ppt, greater than or equal to 300 ppt, greater than or equal to 400 ppt, greater than or equal to 500 ppt, greater than or equal to 600 ppt, greater than or equal to 700 ppt, greater than or equal to 800 ppt, or greater than or equal to 900 ppt. Combinations of the above recited ranges are possible (e.g., the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 1000 ppt and greater than or equal to 1 ppt, the sensing material is capable of detecting the presence of the fluoroalkyl substance at a sensitivity less than or equal to 500 ppt and greater than or equal to 400 ppt). Other ranges are also possible. In certain embodiments, for example, the sensing material is capable of detecting the presence of the fluoroalkyl substance at sub ppt levels.

[0123] In some embodiments, the article comprises a polymer support. For example, referring to FIG. 1, article 102a comprises polymer support 106. According to some embodiments, the polymer support is at least partially functionalized with the sensing material. Referring, for example, to FIG. 1, polymer support 106 is at least partially functionalized with sensing material 104. The sensing material may be disposed (e.g., deposited) on the polymer support, in accordance with some embodiments. In some embodiments, the sensing material coats (e.g., uniformly coats) a surface of the polymer support. In certain embodiments, the polymer support and the sensing material are bonded together (e.g., via one or more covalent bonds, via one or more non-covalent bonds). In some embodiments, for example, the polymer support comprises a material having one or more moieties that are chemically bound to (e.g., chemically functionalized with) the sensing material. In certain embodiments, the polymer support and the sensing material are mixed together via interdiffusion such that at least one atom of the polymer support and at least one atom of the sensing material diffuse into each other. In some embodiments, the polymer support comprises fluorine and is configured to absorb a sensing material comprising fluorine through non-covalent assembly. In certain embodiments, a sensing material comprising fluorine spontaneously absorbs into the polymer support comprising fluorine.

[0124] According to certain embodiments, the polymer support is functionalized with the sensing material by heating the polymer support material in the presence of the sensing material. In some embodiments, for example, heating the polymer support material in the presence of the sensing material comprises heating the polymer support material to a temperature greater than its glass transition temperature. According to some embodiments, the heating process functionalizes the polymer support material with the sensing material.

[0125] In certain embodiments, the polymer support is functionalized with a sensing material comprising a polymer by initiating a polymerization reaction of the polymer at a surface of the polymer support.

[0126] According to certain embodiments, the polymer support (e.g., polymer support 106) is at least partially fluorous. In some embodiments, an at least partially fluorous polymer support may advantageously have an affinity for other materials having fluorous characteristics, including, for example, a fluorinated sensing material and / or fluorinated analytes such as fluoroalkyl substances. In some embodiments, the suitability of a polymer support may be determined by its ability to absorb and / or bind fluorinated materials. In certain embodiments, the polymer support is highly fluorous and does not absorb and / or bind hydrocarbon materials. In some embodiments, the polymer support is configured to absorb and / or bind a fluorinated material (e.g., a sensing material) having a wt.% of fluorine based on a total weight of the fluorinated material that is similar to and / or higher than a wt.% of fluorine in the polymer support based on total weight of the polymer support.

[0127] The polymer support (e.g., polymer support 106) may comprise fluorine in any of a variety of suitable amounts. In certain embodiments, the polymer support comprises fluorine in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 40 wt.%, greater than or equal to 50 wt.%, greater than or equal to 60 wt.%, greater than or equal to 70 wt.%, greater than or equal to 80 wt.%, or greater than or equal to 90 wt.% versus a total weight of the polymer support. In some embodiments, the polymer support comprises fluorine in an amount less than or equal to 99 wt.%, less than or equal to 90 wt.%, less than or equal to 80 wt.%, less than or equal to 70 wt.%, less than or equal to 60 wt.%, less than or equal to 50 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the polymer support. Combinations of the above recited ranges are possible (e.g., the polymer support comprises fluorine in an amount greater than or equal to 10 wt.% and less than or equal to 99 wt.% versus a total weight of the polymer support). Other ranges are also possible. The weight percent of fluorine in a polymer support comprising a polymer may be calculated using the chemical formula of the repeating unit of the polymer and the molecular weight of the repeating unit of the polymer according to equation 2 (Eq. 2) shown above.

[0128] According to some embodiments, the polymer support (e.g., polymer support 106) comprises fluorine at a surface of the polymer support. Referring, for example, to FIG. 1, polymer support 106 comprises fluorine at surface 108a of polymer support 106. In some embodiments, the surface of the polymer support is a surface that is at least partially functionalized with the sensing material. For example, as shown in FIG. 1, surface 108a is functionalized with sensing material 104.

[0129] The polymer support (e.g., polymer support 106) may comprise fluorine at a surface (e.g., surface 108a) of the polymer support in any of a variety of suitable amounts. In some embodiments, for example, the polymer support comprises fluorine at a surface of the polymer support in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 40 wt.%, greater than or equal to 50 wt.%, greater than or equal to 60 wt.%, greater than or equal to 70 wt.%, greater than or equal to 80 wt.%, or greater than or equal to 90 wt.% versus a total weight of the polymer support. In certain embodiments, the polymer support comprises fluorine at a surface of the polymer support in an amount less than or equal to 99 wt.%, less than or equal to 90 wt.%, less than or equal to 80 wt.%, less than or equal to 70 wt.%, less than or equal to 60 wt.%, less than or equal to 50 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the polymer support. Combinations of the above recited ranges are possible (e.g., the polymer support comprise fluorine at a surface of the polymer support in an amount greater than or equal to 10 wt.% and less than or equal to 99 wt.% versus a total weight of the polymer support). Other ranges are also possible. The wt.% of fluorine at a surface of the polymer based on a total weight of the polymer support may be determined using XPS.

[0130] In some embodiments, the polymer support (e.g., polymer support 106) comprises fluorine at a surface (e.g., surface 108a) of the polymer support in an amount greater than or equal to 10 wt.%, greater than or equal to 15 wt.%, greater than or equal to 20 wt.%, greater than or equal to 25 wt.%, greater than or equal to 30 wt.%, greater than or equal to 40 wt.%, greater than or equal to 50 wt.%, greater than or equal to 60 wt.%, greater than or equal to 70 wt.%, greater than or equal to 80 wt.%, or greater than or equal to 90 wt.% versus a total weight of the surface material. In certain embodiments, the polymer support comprises fluorine at a surface of the polymer support in an amount less than or equal to 99 wt.%, less than or equal to 90 wt.%, less than or equal to 80 wt.%, less than or equal to 70 wt.%, less than or equal to 60 wt.%, less than or equal to 50 wt.%, less than or equal to 40 wt.%, less than or equal to 35 wt.%, less than or equal to 30 wt.%, less than or equal to 25 wt.%, less than or equal to 20 wt.%, or less than or equal to 15 wt.% versus a total weight of the surface material. Combinations of the above recited ranges are possible (e.g., the polymer support comprise fluorine at a surface of the polymer support in an amount greater than or equal to 10 wt.% and less than or equal to 99 wt.% versus a total weight of the surface material). Other ranges are also possible. The wt.% of fluorine at a surface of the polymer based on a total weight of the surface material may be determined using XPS.

[0131] According to some embodiments, the polymer support (e.g., polymer support 106) is at least partially porous. In some embodiments, for example, the polymer support comprises a plurality of pores. The plurality of pores may have any of a variety of suitable maximum characteristic dimensions (e.g., greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 10 nm, greater than or equal to 50 nm, greater than or equal to 100 nm, greater than or equal to 500 nm, or greater).

[0132] According to some embodiments, the polymer support (e.g., polymer support 106) comprises a flexible material. In certain embodiments, for example, the polymer support has a flexural modulus less than or equal to 600 MPa, less than or equal to 550 MPa, less than or equal to 500 MPa, or less than or equal to 450 MPa. In some embodiments, the polymer support has a flexural modulus greater than or equal to 400 MPa, greater than or equal to 450 MPa, greater than or equal to 500 MPa, or greater than or equal to 550 MPa. Combinations of the above recited ranges are possible (e.g., the polymer support has a flexural modulus less than or equal to 600 MPa and greater than or equal to 400 MPa). Other ranges are also possible. The flexural modulus of the polymer support may be determined by subjecting the polymer support material to a tensile test, wherein the material is stressed by elongation and the force to create a change in a dimension of the material is measured.

[0133] According to certain embodiments, the flexural modulus of the polymer support does not affect the sensitivity of an article (e.g., sensor) comprising the polymer support. In some embodiments, the flexural modulus of the polymer support is sufficient to translate (e.g., move) an article comprising the polymer support, for example, in a sensing environment, without breaking and / or damaging the polymer support and / or the article, as described herein in greater detail.

[0134] In some embodiments, the polymer support (e.g., polymer support 106) comprises a material that is substantially transparent (e.g., to electromagnetic radiation). For example, in certain embodiments, the polymer support comprises a material that is substantially transparent to: (i) electromagnetic radiation used to excite the sensing material; and / or (ii) electromagnetic radiation emitted from the sensing material. The polymer support (e.g., polymer support 106) may comprise any of a variety of suitable materials. In some embodiments, the polymer support comprises a fluorocarbon polymer. In certain embodiments, the polymer support comprises a perfluoroalkoxy alkane (PFA). According to some embodiments, a PFA is advantageously chemically resistant, temperature resistant up to temperatures of approximately 250 °C, ductile, and amorphous. In certain non-limiting embodiments, a polymer support in the form of a tube comprises PFA. In certain embodiments, the polymer support comprises poly(tetrafluoroethylene) (PTFE). In some non-limiting embodiments, a polymer support in the form of a film comprises PTFE. PFA and / or PTFE are used industrially because purely organic materials do not tend to bind to these polymers. PFA and / or PTFE, however, may advantageously absorb sensing materials comprising fluorine, in accordance with certain embodiments.

[0135] In some embodiments, the polymer support comprises a polymer produced by free radical polymerization of alkenes with perfluoroalkane groups in the monomeric unit, crosslinked networks of polymers containing perfluoroalkane groups, polyethers with perfluoroalkane groups, polyesters with perfluoroalkane groups, polyarylenes with perfluoroalkane groups, poly(arylene ethers) with perfluoroalkane groups, polyimides with perfluoroalkane groups, polyacrylates of polymethacrylates with perfluoroalkane groups and / or polycarbonates with perfluoroalkane groups. Other polymers are also possible.

[0136] In some embodiments, the polymer support comprises cellulose (e.g., modified cellulose, such as a fluorinated modified cellulose). According to some embodiments, the polymer support comprises a poly siloxane (e.g., a fluorinated poly siloxane). In some embodiments the support contains silica, glass, and / or low or high density polyethylene. Other materials (e.g., fluorinated materials) are also possible, as the disclosure is not meant to be limiting in this regard.

[0137] The polymer support may have any of a variety of suitable forms. In certain embodiments, for example, the polymer support is in the form of a film (e.g., a thin film). In certain embodiments, the sensing material is functionalized on a surface of the film. Referring, for example, to FIG. 1, polymer support 106 is in the form of a film, and sensing material 104 is functionalized on surface 108a of the film. According to certain embodiments, the polymer support in the form of a film may be translatable (e.g., moveable) in a sensing environment, as described herein in greater detail. For example, in some embodiments, the polymer support in the form of a film may be translated (e.g., moved) in sensing environment for continuous monitoring of a fluid suspected of comprising an analyte. In some embodiments, a translatable polymer support in the form of a film is advantageous in situations where a response of a sensing material functionalized on the polymer support is irreversible, as the film can be translated to continuously expose fresh, unused sensing material to the fluid.

[0138] In some embodiments, the polymer support is in the form of a tube. FIG. 2 shows a schematic cross-sectional diagram of article 102b comprising polymer support 106 in the form of a tube. As used herein, the term “tube” is given its ordinary meaning and refers to a hollow cylinder for holding or transporting a material (e.g., a fluid such as a liquid and / or a gas). For example, referring to FIG. 2, area 110 of polymer support 106 in the form a tube is hollow.

[0139] In some embodiments, the sensing material is functionalized on an inner surface of the tube. Referring, for example, to FIG. 2, sensing material 104 is functionalized on inner surface 108b of the tube.

[0140] In some embodiments, the polymer support comprises a particle. FIG. 3 shows a schematic cross-sectional diagram of article 102c comprising polymer support 106 comprising a particle.

[0141] The particle may have any of a variety of suitable shapes. In some embodiments, for example, the particle is substantially spherical. In certain embodiments, the particle is nanoparticle. The term “nanoparticle” is used herein in a manner consistent with its ordinary meaning in the art. Nanoparticles are particles having a maximum characteristic dimension from 1 nanometer to 1 micrometer. According to some embodiments, the maximum characteristic dimension of the nanoparticle is from 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 recited ranges are possible (e.g., 300 nanometers to 700 nanometers, or 200 nanometers to 1 micrometer). Other ranges are also possible. In some embodiments, the particle is a microparticle. The term “microparticle” is used herein in a manner consistent with its ordinary meaning in the art. Microparticles are particles having a maximum characteristic dimension (e.g., a maximum diameter) from 1 micrometer to 1000 micrometers.

[0142] In certain embodiments, the particle is a millimeter scale particle. In certain embodiments, for example, the millimeter scale particle has a maximum characteristic dimension greater than or equal to 1 mm (e.g., greater than or equal to 2 mm, greater than or equal to 5 mm, etc.).

[0143] The maximum characteristic dimension of the particle (e.g., nanoparticle, microparticle, millimeter scale particle) may be determined by electron microscopy techniques (e.g., scanning electron microscopy and / or transmission electron microscopy).

[0144] In some embodiments, the sensing material is functionalized on a surface of the particle. Referring, for example, to FIG. 3, sensing material 104 is functionalized on surface 108c of the particle.

[0145] In some embodiments, the polymer support (e.g., at least partially functionalized with the sensing material) is deposited on (e.g., coated on) a surface of a substrate. FIG. 4A shows a cross-sectional schematic diagram of article 102d comprising polymer support 106 deposited on (e.g., coated on) surface 112a of substrate 114a. As shown in FIG. 4A, polymer support 106 is at least partially functionalized with sensing material 104 such that sensing material 104 is functionalized on surface 108d of polymer support 106.

[0146] The substrate may have any of a variety of suitable forms. In some embodiments, for example, the substrate is in the form of a film (e.g., a thin film). For example, referring to FIG. 4A, substrate 114a is in the form of a film. According to certain embodiments, the substrate in the form of a film may be translatable (e.g., movable), as described herein in greater detail with respect to the polymer support.

[0147] According to certain embodiments, the substrate (e.g., substrate 114a) is a filter and / or membrane. In certain embodiments, for example, the substrate (e.g., filter and / or membrane) is part of a filtration system and / or a chemical reactor (e.g., a flow based chemical reactor). The filter and / or membrane may, in some embodiments, be configured to filter a fluid (e.g., a gas such as air and / or a liquid such as water). In certain embodiments, the filter and / or membrane can also be a sensor.

[0148] According to certain embodiments, the substrate is in the form of a particle. FIG. 4B shows a cross-sectional schematic diagram of article 102e comprising polymer support 106 deposited on (e.g., coated on) surface 112b of substrate 114b in the form of a particle. The particle may have any of a variety of suitable shapes and / or sizes (e.g., the particle may be a nanoparticle, microparticle, or millimeter scale particle).

[0149] The substrate (e.g., substrate 114a and / or 114b) may comprise any of a variety of suitable materials. In some embodiments, for example, the substrate comprises a polymer. In certain embodiments, the substrate (e.g., in the form of a film) comprises glass. In certain embodiments, the substrate (e.g., in the form of a particle) comprises silica. Other substrates and / or substrate materials are also possible as the disclosure is not meant to be limiting in this regard.

[0150] The polymer support may be deposited on (e.g., coated on) the substrate via any of a variety of suitable mechanisms. In certain embodiments, for example, the polymer support is deposited on the substrate via spin coating, dip coating, spray coating, drop casting, blade coating, doctor blading, electrospinning, inkjet printing, and / or chemical vapor deposition (CVD). Other deposition mechanisms are also possible.

[0151] In some embodiments, the substrate is reacted with a fluorine-containing surface modification agent. According to some embodiments, the substrate is reacted with a fluorine-containing surface modification agent via a radical reaction, a nucleophilic substitution, a carbene reaction, a transesterification reaction, an insertion reaction, a metal catalyzed reaction. Other reaction mechanism are also possible.

[0152] In certain embodiments, the polymer support is functionalized with the sensing material prior to depositing the polymer support on the substrate. In other embodiments, the polymer support is functionalized with the sensing material after depositing the polymer support on the substrate.

[0153] The article may comprise (and / or be in wired and / or wireless communication with) one or more additional components not shown in the figures. For example, in some embodiments, the article comprises (and / or is in wired and / or wireless communication with) circuitry and / or electronics for signal conditioning, readout, and / or output, such as one or more multiplexers, analog-to-digital converters, bridge circuits, and / or microcontrollers. In some embodiments, the article comprises (and / or is in wired and / or wireless electrical communication with) one or more detectors and / or readers, which may be coupled to the circuitry and / or electronics. In certain embodiments, the article comprises (and / or is in wired and / or wireless electrical communication with) one or more data acquisition and / or processing units, which may be coupled to the circuitry and / or electronics. In some embodiments, the one or more data acquisition and / or processing units may be configured to receive a readout and / or output from the article and execute data processing of the readout and / or output based on instructions (e.g., memory storing instructions).

[0154] The articles described herein may be implemented in any of a variety of suitable applications, including, for example, filtration systems and / or a chemical reactors (e.g., flow based chemical reactors). In certain embodiments, the articles described herein are hand-held devices used for portable applications (e.g., field testing). Other applications are also possible.

[0155] Systems for detecting an analyte (e.g., a fluoroalkyl substance) are also described. In some embodiments, a system comprises an article as described in greater detail herein. The article may be fluidically connected to one or more reservoirs and / or sources of a fluid. In certain embodiments, the article and / or the one or more reservoirs and / or sources of the fluid may be fluidically connected to one or more pumps (e.g., recirculating pumps), fans, and / or gravity feeds configured to facilitate flow (e.g., continuous flow) of a fluid from the one or more reservoirs and / or sources of the fluid to the article.

[0156] According to some embodiments, a method of detecting and / or determining an analyte (e.g., a fluoroalkyl substance) is described. In some embodiments, the fluoroalkyl substance is a perfluoroalkyl substance and / or a polyfluoroalkyl substance. In certain embodiments, the method comprises exposing an article (e.g., as described herein in greater detail) to a fluid suspected of comprising the analyte (e.g., fluoroalkyl substance). FIG. 5 shows a cross-sectional schematic diagram representing a method of exposing article 102a to fluid 116 suspected of comprising an analyte (e.g., a fluoroalkyl substance). In certain embodiments, for example, as described herein with reference to FIG. 1, article 102a comprises polymer support 106 (e.g., in the form of a film) at least partially functionalized with sensing material 104, wherein polymer support 106 comprises fluorine in an amount greater than or equal to 10 wt.% (e.g., greater than or equal to 20 wt.%, greater than or equal to 30 wt.%) versus a total weight of polymer support 106. In some embodiments, exposing the article to the fluid suspected of comprising the analyte comprises contacting the sensing material with the fluid suspected of comprising the analyte. Referring, for example, to FIG. 5, exposing article 102a to fluid 116 suspected of comprising the analyte comprises contacting sensing material 104 with fluid 116 suspected of comprising the analyte. In some embodiments, although not shown in the figures, exposing the article to the fluid suspected of comprising the analyte comprises contacting the polymer support with the fluid suspected of comprising the analyte.

[0157] According to certain embodiments, exposing the article to the fluid suspected of comprising the analyte comprises translating (e.g., moving) at least a portion of the article in a sensing environment comprising the fluid. Referring, for example, to FIG. 5, exposing article 102a (e.g., in the form of a film) to fluid 116 comprises translating article 102a in a sensing environment comprising fluid 116. In some embodiments, as described herein in greater detail, translating at least the portion of the article in the sensing environment comprising the fluid is advantageous for continuous monitoring of the fluid, even in situations where a response of the sensing material functionalized on the polymer support is irreversible, as the article can be translated to continuously expose fresh, unused sensing material to the fluid.

[0158] In certain embodiments, the flexural modulus of the polymer support is sufficient to translate (e.g., move) the article (e.g., in the form of a film) without breaking and / or damaging the polymer support and / or the article. For example, in some embodiments, the sensing environment comprising the fluid is a sensing chamber, and translating the article in the sensing environment comprises pulling the article under tension through the sensing chamber. The polymer support may, in certain embodiments, have a sufficient flexural modulus such that the article does not break and / or is not damaged when pulled. In certain embodiments, resistance to translation of the article may be caused by compression seals and / or gaskets that contain the fluid within the sensing chamber. In some embodiments, the compression seals and / or gaskets overlay the article.

[0159] As described herein in greater detail with reference to FIG. 2, in some embodiments, polymer support 106 is in the form of a tube and sensing material 104 is functionalized on inner surface 108b of the tube. In some such embodiments, the exposing comprises flowing the fluid suspecting of comprising the analyte (e.g., fluoroalkyl substance) through the tube such that the analyte (e.g., fluoroalkyl substance), if present, is exposed to the sensing material functionalized on the inner surface of the tube. FIG. 6 shows a schematic diagram representing a method of flowing fluid 116 suspected of comprising an analyte through a tube. As shown in FIG. 6, article 102b comprises polymer support 106 in the form of a tube. In some embodiments, as fluid 116 flows through the tube, fluid 116 suspected of comprising an analyte is exposed to sensing material 104 functionalized on inner surface 108b of the tube.

[0160] According to certain embodiments, the fluid comprises at least one liquid (e.g., at least two liquids, at least three liquids, at least four liquids, etc.). According to some embodiments, the at least one liquid is or comprises the analyte (e.g., the fluoroalkyl substance).

[0161] In some embodiments, the fluid comprises a solution comprising at least one liquid and an analyte (e.g., fluoroalkyl substance) dissolved in the at least one liquid. In certain embodiments, for example, the fluid (e.g., solution) comprises water. The water may be sourced from any of a variety of suitable sources, including, for example, a home, a well, a body of water (e.g., an ocean, a sea, a pond, a lake, a river, and the like), a residential unit, a commercial unit, an industrial plant, a semiconducting manufacturing site, a water treatment site, a water distribution site, a food manufacturing site, an industrial waste steam, a landfill leachate, a contaminated site, a (pre)concentrator system, an irrigation source, and / or a landfill. Other water sources are also possible. In certain embodiments, for example, the water is sourced from food.

[0162] In some embodiments, the fluid (e.g., solution) comprises at least one organic solvent. In certain embodiments, the fluid (e.g., solution) comprises water and at least one organic solvent.

[0163] According to some embodiments, the fluid comprises at least one gas (e.g., at least two gases, at least three gases, at least four gases, etc.). In certain embodiments, the at least one gas is or comprises the analyte (e.g., the fluoroalkyl substance).

[0164] In certain embodiments, the gas comprises less than or equal to 8 carbon atoms (e.g. less than or equal to 6 carbon atoms, less than or equal to 5 carbon atoms, less than or equal to 4 carbon atoms, etc.). In some embodiments, the gas comprises at least one fluoroalkyl moiety.

[0165] In certain embodiments, the fluid comprises a mixture of gases comprising oxygen, nitrogen, carbon monoxide, carbon dioxide, and / or combinations thereof.

[0166] According to some embodiments, the fluid comprises an aerosol (e.g., a suspension of solid particles or liquid droplets in a gas).

[0167] In some embodiments, the fluid is or comprises a refrigerant.

[0168] In other embodiments the fluoroalkane is used as a refrigerant.

[0169] In some embodiments, the method comprises detecting a change in electromagnetic radiation emission of the sensing material. According to some embodiments, the detecting comprises continuously detecting the change in electromagnetic radiation emission of the sensing material. The detecting may, in some embodiments, reveal information about the composition of the analyte (e.g., the fluoroalkyl substance) (e.g., a presence of the analyte, an amount of the analyte), as described herein in greater detail.

[0170] In certain embodiments wherein the polymer support is in the form of a tube, the detecting comprises detecting the change in electromagnetic radiation emission of the sensing material as a function of time and / or position within the tube. For example, referring to FIG. 6, detecting the change in electromagnetic radiation emission of the sensing material may occur at points 602a, 602b, 602c, 602d, and / or 602e as fluid 116 flows through the tube. Although FIG. 6 shows five detection points, the method may comprise detecting the change in electromagnetic radiation at any of a variety of suitable points (e.g., two points, ten points, twenty points, one hundred points, etc.). According to some embodiments, detecting the change in electromagnetic radiation emission of the sensing material as a function of time and / or position within the tube may advantageously determine whether a fluid has gained or lost a presence of (and / or an amount of) analyte as the fluid flows through the tube.

[0171] In some embodiments, the detecting comprises detecting the change in electromagnetic radiation emission using a detector and / or reader. According to certain embodiments, the detector and / or reader may be in wired and / or wireless communication with the article and / or sensing material. For example, in some embodiments, the detector and / or reader is in direct electrical communication with the article (e.g., with circuitry and / or electronics of the article). According to some embodiments, the detector and / or reader is in wireless electrical communication with the article.

[0172] Any of a variety of detectors and / or readers may be used to detect the change in electromagnetic radiation (e.g., light) emission (e.g., of the at least one chromophore, of the coupled- multichromophore). In certain embodiments, for example, the detector and / or reader is a fluorescence spectrometer, a photodiode, a photovoltaic device, an individual’s eyes (e.g., detecting a visible colorimetric change), and / or a smartphone. Other detectors and / or readers are also possible.

[0173] In some embodiments, the method of detecting and / or determining the analyte (e.g., fluoroalkyl substance) comprises detecting a presence of and / or determining an amount of the analyte (e.g., fluoroalkyl substance), if present, based on the change in electromagnetic radiation emission of the sensing material. In certain embodiments, the method of detecting the analyte (e.g., fluoroalkyl substance) comprises detecting a presence of the analyte (e.g., fluoroalkyl substance), if present, based on the change in electromagnetic radiation emission of the sensing material. For example, in some embodiments, the change in electromagnetic radiation emission of the sensing material (e.g., of at least one chromophore, of a coupled-multichromophore) is indicative of a presence of the analyte.

[0174] In some embodiments, the method of determining the analyte (e.g., fluoroalkyl substance) comprises determining an amount of the analyte (e.g., fluoroalkyl substance), if present, based on the change in electromagnetic radiation of the sensing material. In certain embodiments, for example, the change in electromagnetic radiation emission of the sensing material (e.g., of at least one chromophore, of a coupled- multichromophore) is indicative of an amount (e.g., concentration) of the analyte (e.g., fluoroalkyl substance). In some embodiments, a ratiometric change in electromagnetic radiation emission of the sensing material (e.g., of a coupled- multichromophore) is indicative of an amount (e.g., concentration) of the analyte (e.g., fluoroalkyl substance). For example, in some embodiments, the change in electromagnetic radiation emission of at least one chromophore is directly proportional to a concentration the analyte (e.g., fluoroalkyl substance).

[0175] In certain embodiments, the analyte described herein is a fluoroalkyl substance. As used herein, the term “fluoroalkyl substance” refers to a molecule comprising an alkyl group in which one or more hydrogens have been substituted with fluorine. The fluoroalkyl substance may be any of a variety of suitable fluoroalkyl substances. In certain embodiments, the fluoroalkyl substance is a per- or poly-fluoroalkyl substance (PFAS). In certain embodiments, the fluoroalkyl substance comprises 2-(N-methyl- perfluorooctane sulfonamido) acetic acid, perfluorobutane sulfonic acid, perfluorohexane sulfonic acid, perfluoroheptanoic acid, perfluorooctane sulfonic acid, perfluoromethylheptane sulfonic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, trifluoroacetic acid, conjugates thereof, and / or combinations thereof. Other fluoroalkyl substances are also possible.

[0176] According to some embodiments, the fluoroalkyl substance is a Brpnstcd acid. As used herein, the term “Brpnsted acid” is given its ordinary meaning in the field of chemistry and refers to a species that is capable of donating a proton (H+).

[0177] International Patent Application No. PCT / US2023 / 082090, filed December 1, 2023, and entitled “Compositions for Detection of Fluorocarbons and Related Articles, Systems, and Methods,” and U.S. Provisional Patent Application No. 63 / 656,055, filed June 4, 2024, and entitled “Articles, Systems, and Methods for Detection of Fluoroalkyl Substances,” are incorporated herein by reference in their entirety for all purposes.

[0178] The following example is intended to illustrate certain embodiments of the present invention, but does not exemplify the full scope of the invention.

[0179] EXAMPLE 1

[0180] The following example describes a platform for ultrasensitive and continuous PFAS detection.

[0181] Fluorescent based detection methods for PFAS sensing based on multiple transduction schemes are described in International Patent Application No. PCT / US2023 / 082090, filed December 1, 2023, and entitled “Compositions for Detection of Fluorocarbons and Related Articles, Systems, and Methods,” which is incorporated herein by reference in its entirety for all purposes. The fluorescent based detection methods revealed that particles comprising a sensing material demonstrated superior sensitivity as compared to coatings as a result of the greater interfacial area and ability to mix in solution. Described herein is a polymer support that can be used as a substrate for PFAS sensing. In some embodiments, the polymer support comprises a perfluoroalkoxy alkane (PFA) polymer. PFA based tubing is widely used in flow based chemical reactors due to its resistance to having materials stick to it, its ductility, and its temperature resistance (e.g., it can be used up to temperatures of approximately 250°C). Furthermore, the PFA material is amorphous and thereby minimizes scattering light to allow for optical interrogation through the polymer tubing. Also described herein is a functionalization scheme in which a substrate polymer (e.g., PFA based tubing) is heated over its glass transition temperature in the presence of a sensing material. The functionalization process creates a coating on the substrate polymer, resulting in superior sensing responses to PFAS. Furthermore, the use of functionalized tubing allows for a continuous process of PFAS monitoring.

[0182] Prior to functionalization with a sensing material, the PFA tubing may be cleaned. In some embodiments, the PFA tubing is cleaned via a hot water extraction. In certain embodiments, the PFA tubing is cleaned using via an extraction using basic water with a high pH. In some embodiments, the PFA tubing is cleaned via an extraction with organic solvents including chloroform, toluene, anisole, methanol, and / or acetone. Other extraction and / or cleaning methods are also possible.

[0183] In some embodiments, the sensing material comprises ACA54 (FIG. 7). In certain embodiments, PFA based tubing is functionalized with the ACA54 sensing material by filling the tubing with a solution containing ACA54, heating the tubing to higher than 90 °C for 10-60 minutes, and then removing the solution. The result is a very uniform coating throughout the tubing. The tubing can be used to detect PFAS chemicals in aqueous solutions by flowing water through the tubing for different amounts of time. Longer flow times allow for greater signals and lower limits of detection. Monitoring can be done in real time on an industrial waste stream, or a volume of water can be flowed through the system using a recirculating pump system or gravity feed. For example, in some cases, a device can be simply inverted multiple times to pass a water sample though a tube connecting two reservoirs. The systems and devices described herein can be used for portable applications. The presence or absence of PFAS is determined by monitoring fluorescence from the tubing. The monitoring can be performed by measuring emission at one wavelength or at two separate wavelengths. In the latter, a ratio of emission intensities can be used to determine the concentration of PFAS. The response of PFA based tubing functionalized with ACA54 to PFAS is shown in FIGS. 8-9.

[0184] The functionalization conditions of the tubing are important, and films coated at lower temperatures may produce minimal response to PFAS. Accordingly, heating the PFA results in the interdiffusion of the ACA54 into the PFA, which shows an optimal response. This is consistent with previous results wherein films showed lower sensitivity relative to particles. When allowed to assemble with thermal processing, the PFA support in combination with the sensing material creates a composition that displays superior sensing performance. PFA is available in tubing form, but the same advantage can be obtained if PFA fibers, particles, or lens materials are coated with the sensing material. FIGS. 10A-10C show examples of PFA based tubing functionalized with other exemplary sensing materials.

[0185] PFA polymers have a range of compositions and in some embodiments have the structure shown in FIG. 11, wherein x and y are the relative fraction of each repeating unit in the polymer and n represents the number of repeating units in the polymer chain. The polymer support should have low light scattering properties, be flexible, have good mechanical properties, and have affinity for fluorous materials. Other polymers that have these attributes may also serve as suitable substrates for the formation of a sensing composition.

[0186] The PFA polymers and related polymers have fluorous character, which implies that they have an affinity for other materials with fluorous characteristics. Organic polymers that generally have 10% or more (e.g., 20% or more, 30% or more, 40% or more, 50% or more, etc.) by weight fluorine are suitable as fluorous polymer supports. In some embodiments, the polymer support comprises a polymer produced by free radical polymerization of perfluoroalkane groups in the monomeric unit, crosslinked networks of polymers containing perfluoroalkane groups, polyethers with perfluoroalkane groups, polyesters with perfluoroalkane groups, polyarylenes with perfluoroalkane groups, poly(arylene ethers) with perfluoroalkane groups, polyimides with perfluoroalkane groups, and / or polycarbonates with perfluoroalkane groups.

[0187] Polymer supports that do not have fluorous characteristics are not as effective for sensing. For example, absorbing a sensing material into poly(dimethyl siloxane) tubing results in a material that has a very minimal response to PFOA at 50 ppb with one hour of flow time as shown in FIGS. 12-14.

[0188] The sensing material can be: (i) polymeric (e.g., as in the case of ACA54 (FIG. 7)); (ii) a combination of a polymer or macromolecule with a molecular weight over 3,000 Da; (iii) a molecule with a molecular weight less than 3,000 Da; (iv) and / or composed of molecules with molecular weights under 3,000 Da. In some embodiments, the sensing material comprises a polymer comprising a light harvesting group and a responsive group (FIG. 15A). Examples of light harvesting groups are shown in FIG. 15B, and examples of responsive groups are shown in FIG. 15C.

[0189] In some embodiments, a sensing material comprises a polymer and a small molecule. The binding of a fluoroalkyl species can modify the polymer-small molecule interaction to change the fluorescence response of the sensing material. In one representative example, the sensing material comprises one or more of the materials shown in FIGS. 16A-16D. Other examples involve only small molecules in which the fluorescence is quenched, and after the binding with acidic fluorocarbons, the fluorescence increases.

[0190] Sensing materials can contain multiple polymers and small molecules. They may also include other additives including fluorocarbon surfactants of polymers (such as Zonyl or Krytox) that do not directly impact the fluorescence processes in the materials, but stabilize the compositions or enhance the response to PFAS.

[0191] Sensing signals can involve measuring total fluorescence and ratios of emissions at different wavelengths. Continuous monitoring can include a time dependence on the measurement. For trace measurements, the amount of mass of analyte transferred to the sensing materials is generally limiting. With a continuous flow of water past the sensing material, longer exposure times will generally result in larger responses and lower detection limits. A time-response profile can be important and continuous monitoring can be used to best manage water treatment or determine sources of PFAS in waste streams.

[0192] PFAS can be detected at lower concentrations by longer exposure times and larger sample volumes. For example, the sensing material shown in FIG. 7 when optimized by stabilization by Zonyl is capable of detecting PFOA at 25 ppt by circulating 25 mL of a water solution comprising the PFOA for 1 hour. With a larger volume of solvent and longer cycling time, sub ppt levels of detection can be achieved.

[0193] In flow experiments (FIG. 17) with the material shown in FIG. 7, it is found that the fluorescence is affected more at the terminal part of the tubing than the initial part. This is not a function of turbulence in the tubing and kinking the tubing does not appear to affect the position of the maximum fluorescent effect. This result shown in FIG. 18 is indicative of the transport of the PFAS along the tubing. It is anticipated that different PFAS materials will have different rates of diffusion and that this type of chromatographic separation can provide a mechanism for discriminating different PFAS compounds and PFAS from other interf erants. In some embodiments, a temporal profile produced by monitoring the fluorescence response along the tube can be used to make determinations about the PFAS concentrations (FIG. 19).

[0194] Another sensing mechanism is to turn on an entirely new fluorescence. This can be in the form of causing a system to absorb excitation light become fluorescent. This scheme can be a poly chromophore or isolated chromophores. In one embodiment, a PFAS compound binding to a sensing molecule prevents single electron transfer reactions from a donor group to a photo-oxidizing chromophore. The excitation of the chromophore creates an unfilled orbital that can accept an electron from a proximate amine. The system then resets with back electron transfer from the photo-reduced chromophore to the oxidized amine. By placing the chromophore and amine in a fluorous environment that absorbs PFAS compounds, a proton transfer reaction can be triggered with PFAS binding. A non-limiting example is an amine proximate to an anthracene chromophore that will be quenched in the absence of a PFAS but emissive in the presence of PFAS because of protonation of the amine, which prevents electron transfer quenching (FIG. 20).

[0195] In some examples the amine is connected through a covalent bond to the chromophore, but in other cases the amine could be proximate in a non-covalent assembly. As shown in FIG. 20, the amine can be substituted with R groups that in some cases can be fluorophilic groups. In some cases, one or more of the R groups has a structure with at least 3 consecutive carbons containing 1-3 fluorine atoms. The anion in in FIG. 20 comprises a PFAS molecule. The chromophore also need not be an anthracene and can be other small molecule chromophores, multichromophores, or a polymer. The chromophore for this process can be one that can undergo electron transfer quenching by the donor group, which in the example given is an amine. Many chromophores are possible provided they have the proper excited state oxidizing power to be quenched by the donor, and the isolated amine is but one of many possibilities. Other non-limiting examples of donors are electron rich aromatic rings, inorganic complexes, sulfides, and / or organic anions. Energy migration from a multichromophore system can also be used to enhance the turn on emission.

[0196] Quenching can in other cases also be achieved by PFAS action through methods that do not necessarily involve electron transfer. For example, PFAS action can generate a new species that accepts energy from a chromophore or polychromophore and thereby quenches the fluorescence. An exemplary compound is shown in FIG. 21. The compound is colorless and not capable of fluorescence quenching in its neutral state, but is transformed to a colored compound capable of absorbing energy from a chromophore. The R groups in FIG. 21 can comprise groups that provide fluorophilic characteristics. Additionally, in some embodiments, it may be useful to have one or more OR groups in place of the other groups attached to the aromatic rings. There are families of emissive reactive dyes that can similarly ionize with acid activation that can be used to detect PFAS. Additionally, other groups can be appended to the rings to rigidify the compounds or shift the absorption. In some cases, the ionized compounds can be emissive. Energy migration through a polychromophoric system containing these reactive groups can be used to create superior signals.

[0197] In some embodiments it may be desirable to have the PFAS binding reduce the fluorescence in what would be termed a turn off response. In this case, the PFAS can be used to produce a quenching species. In one embodiment, a PFAS molecule can protonate a molecule and thereby increase its electron affinity and cause it to have sufficient oxidizing power to quench a proximate chromophore. In this case the PFAS activated acceptor has the ability to accept an electron from a photo-excited chromophore. The associated electron transfer and back electron transfer results in a deactivation of the chromophore and a turn off (quenching) of the emission. A number of different classes of PFAS activated compounds can display this behavior including pyridyls, imines, ketones, or inorganic ions. In some embodiments that transfer of the PFAS into the sensing layer can be used to catalytically generate quenchers or produce new fluorescence. There are many examples of groups that can be catalytically removed by action of acid. The absorption of PFAS into the sensing material can be used to create acidity that produces this catalytic chemistry. In some cases, the chemistry will work with one or more equivalents of water. In these schemes the reaction may be called an acid catalyzed hydrolysis. In some embodiments, the catalytic removal of a group will change the electron donating ability of a group. In certain cases, this will result in the ability of the group to delocalize electrons and generate an enhanced emission. A non-limiting example is the catalytic removal of what is often referred to as a t-BOC group. The t-BOC group reduces the electron donating ability of the phenolic oxygen to which it is attached. When the t-BOC is catalytically removed by the PFAS induced acidity in the sensing material, the liberated phenol will result in a red shifted. Two non-limiting examples are shown in FIGS. 22-23 wherein a phenol is liberated to create an enhanced emission.

[0198] In the examples shown in FIGS. 22-23, the R groups can in some cases comprise a fluorophilic group that attracts the PFAS. The acid catalyzed decomposition of the t- BOC group creates carbon dioxide and organic products. This type of hydrolysis scheme is not limited to t-BOC groups and can be applied to a wide variety of substrates. General example groups that can be catalytically removed by acid to enhance the electron donating ability of a Z group are shown in FIG. 24.

[0199] In some embodiments, referring to FIG. 24, the Z group in can be oxygen, sulfur, and / or a NR; the R groups can comprise a fluorophilic element; the Y groups can be a group that activates the cleavage of the carbon bound to the Z groups. In some cases, the Y groups are oxygen, sulfur, PR, and / or a NR.

[0200] Other acid catalyzed reactions resulting from PFAS absorption to a sensing material can also be used to change fluorescence. In some embodiments, an electron accepting group can be produced. This electron accepting group can be used to quench fluorescence by an electron transfer process. In one non-limiting example shown in FIG. 25, an acetal can be hydrolyzed to produce a quinone that is an electron accepting group capable of quenching fluorescence. In this example, the R groups can comprise fluorophilic groups that help attract PFAS and / or groups to adjust the reactivity or electron affinity. In some cases, ketones generated by catalytic hydrolysis can produce an expanded chromophore. In some embodiments, the ketone is in conjugation with a donor group. In one non-limiting example shown in FIG. 26, the generation of a ketone connected to an amino-aromatic group generates a new emissive material. There are many examples of emissive chromophores that contain ketones. Other reactions including the hydrolysis of imines can be used to create new chromophores. The chromophores can be part of a polychromophore system or be in a polymer.

[0201] There are an abundance of acid catalyzed or stoichiometric reactions that result in unveiling relevant functional groups. These reactions are often used in organic synthesis in the form of a protective group that prevents unwanted reactivity in one step, but then can be removed in subsequent steps. Many other ways to create PFAS sensing materials using established methods are possible (see Protective Groups in Organic Synthesis, 2ndEd. T. W. Greene and P. G. M. Wuts, John Wiley and Sons. 1990, which is incorporated herein by reference in its entirety for all purposes). Other acid catalyzed reactions are anticipated such as hydrolysis of vinyl ethers, elimination reactions to create new double bonds, cleavage of oxygen-silicon bonds, ester hydrolysis, and Beckman rearrangements.

[0202] In some embodiments, the reactions induced by PFAS may require some heating or removal from the water solution. Removal from water can result in dehydration and enhanced acidity in the sensing material.

[0203] PFAS contains by definition high levels of fluorine. Highly reducing chromophores that when photoactivated can act upon PFAS to liberate fluoride ions. Fluoride ions are well known to react with organo silicon compounds and Si-C, Si-N, or Si-0 bonds. In some embodiments, these bond cleavages will be capable of creating new chromophores capable of turn off or turn on changes in a fluorescence signal or creating a new fluorescence signal.

[0204] In some embodiments, a sensing composition capable of detecting PFAS chemicals in water at concentrations less than 10 ppt is described, the sensing composition comprising a flexible, transparent polymer support containing more than 30% by weight fluorine that is functionalized with a sensing material.

[0205] In certain embodiments, the sensing material is absorbed on the polymer support from a solution at a temperature around or above the glass transition temperature of the polymer support. In some embodiments, the sensing material is a fluorescence material with a quantum yield in excess of 30%.

[0206] In certain embodiments, the sensing material is more than 45% fluorine by weight.

[0207] In some embodiments, the sensing material comprises a basic nitrogen heterocycle that is capable of producing a new fluorescence when interacting with a PFAS molecule.

[0208] In certain embodiments, the sensing material contains a guest chromophore that is excited indirectly by energy transfer and the efficiency of energy transfer is changed by the presence of a PFAS molecule.

[0209] In certain embodiments, the sensing material displays a change in emission in response to PFAS. In some embodiments, the sensing material displays a change in emission lifetime in response to PFAS. In certain embodiments, the sensing material displays a change in emission as a result of a PFAS catalyzed reaction. In some embodiments, the sensing material displays a change in emission as a result of a PFAS induced hydrolysis. In certain embodiments, the sensing material displays a change in emission as a result of a PFAS induced electron transfer quenching.

[0210] In some embodiments, a method of using a composition in a sensor is described, wherein the sensor can be operated continuously.

[0211] In certain embodiments, the time dependence and position of the fluorescence in in the sensor can be used to determine PFAS concentrations and characteristics of a water sample.

[0212] EXAMPLE 2

[0213] The following example describes sensing material that bind to PFA tubing.

[0214] FIG. 27A (top) shows a non-limiting example of a PPE-Py polymer having greater than or equal to 30 wt.% and less than or equal to 40 wt.% (e.g., 31.4 wt.%) fluorine versus a total weight of the polymer. The polymer absorbs to a surface of PFA tubing. FIG. 27A (bottom) shows that the polymer fluoresces after functionalization to the PFA tubing. The PFA tubing becomes brightly fluorescent after functionalization, as shown in the inset. FIG. 27B (top) shows a non-limiting example of a PPE-Py polymer having greater than or equal to 30 wt.% and less than or equal to 40 wt.% (e.g., 39.3 wt.%) fluorine versus a total weight of the polymer. The polymer absorbs to a surface of PFA tubing. FIG 27B (bottom) shows that the polymer fluorescence after functionalization to the PFA tubing. The PFA tubing becomes brightly fluorescent after functionalization, as shown in the inset.

[0215] FIG. 27C shows non-limiting examples of polymers having greater than or equal to 20 wt.% and less than or equal to 30 wt.% fluorine versus a total weight of the polymers. The polymers absorb to fluorocarbon surfaces such as PFA tubing.

[0216] FIGS. 30A-30E show non-limiting examples of sensing materials with various fluorine weight percentages, wherein the sensing materials bind to PFA tubing. FIG. 30F shows the fluorescence of emission of the polymer shown in FIGS. 30A-30E. As shown in FIG. 30F, the PFA tubing without a polymer shows no fluorescent emission, and the polymer having 0 wt.% fluorine based on a total weight of the polymer has minimal fluorescent emission. Polymers having greater than or equal to 10 wt.% to less than or equal to 40 wt.% fluorine based on a total weight of the polymer display fluorescent emissions.

[0217] EXAMPLE 3

[0218] The following example describes sensing materials that bind to particles.

[0219] FIG. 28A shows, according to certain embodiments, the functionalization of sensing materials on silica nanoparticles and spheres. The silica nanoparticles or spheres are first treated with a fluorous surface modification agent that introduces fluorous character to cause binding of the sensing material to the fluorous coating on the particle surface. FIGS. 28B-28D show, according to certain embodiments, the fluorescence of the sensing materials after functionalizing the silica nanoparticles and spheres with the fluorous surface modification agent and the sensing material.

[0220] EXAMPLE 4

[0221] The following example describes sensing material for vapor sensing.

[0222] FIG. 29A shows a non-limiting example of a sensor material for PFAS vapor sensing. A peak fluorescence emission of the sensing material shifts in wavelength after 15 seconds of exposure to trifluoroacetic acid (TFA) vapor, as shown in FIG. 29B. After removal of the TFA vapor, the fluorescence emission of the sensing material recovers to its initial peak fluorescence emission, as shown in FIG. 29C.

[0223] Annealing of PFOA at 100 °C (b.p. 190 °C) generated perfluorooctanoic acid (PFOA) vapors that completely activated the polymer. As shown in FIG. 29D, the peak fluorescence emission of the sensing material also shifts in wavelength after exposure to PFOA vapor.

[0224] EXAMPLE 5

[0225] The following example describes materials and methods used to synthesize sensing materials.

[0226] Materials

[0227] All reactions were carried out under argon using oven-dried glassware. Flash column chromatography was carried out using silica gel (high-purity grade, pore size 60 A, 230-400 mesh particle size, Sigma Aldrich). Commercial reagents and solvents were purchased from Sigma Aldrich, SynQuest, Ambeed or VWR, and were used without further purification. Toluene was 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 Nanopure™ Analytical Ultrapure Water System (Thermo Fisher Scientific). Pentiptycene diacetylene 1, fluorinated pseudo-pentiptycene diacetylene 2, fluorinated diiodobenzene 3, fluorinated dibromo fluorene 4, and fluorinated fluorene diboronic ester 5 (see FIG. 31) were prepared following previously reported procedures.

[0228] Instruments and19F NMR spectra were recorded using a three-channel Bruker Avance Neo spectrometer operating at 400.17 MHz. Molecular weight and dispersity of the polymers was obtained using an Agilent 1260 Infinity system equipped with an Agilent PLgel guard column (5 pm; 50 x 7.5 mm) and three Agilent PLgel analytical columns (5 pm; 300 x 7.5 mm; 105, 104, and 103A pore sizes). The instrument was calibrated with polystyrene standards between 1.7 and 3150 kg mol-1. All samples were prepared in HPLC-grade tetrahydrofuran. Each run was performed at a 1.0 mLmin-1flow rate and 35 °C. Molecular weight values were calculated using ChemStation GPC Data Analysis Software (rev. B.01.01) based on the refractive index signal. Fluorescence measurements were performed using a Horiba Quanta-(|) fluorescence spectrophotometer, using right-angle detection with an optical fiber.

[0229] General procedures for monomer synthesis 6,12-Dihydroindeno[l,2-Z?]fluorene (6, 0.491 g, 1.93 mmol) and 3- (perfluorooctyl)propyl iodide (5 g, 8.50 mmol) were dissolved in DMSO (15 mL). Then, an aqueous solution of potassium hydroxide (4.31 g, 77.2 mmol, in 8.5 mL H2O) and tetrabutylammonium bromide (0.312 g, 0.965 mmol) were added to the reaction flask. The mixture was stirred at 90 °C for 24 h under argon atmosphere. Then, the mixture was allowed to cool down to r.t., poured into water and extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous sodium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiCL, AcOEt / hexanes, 5 / 95) obtaining 7 (4.04 g, 49 %) as white solid.!H NMR (400 MHz, CDCh) 6: 7.80 (d, J= 7.4 Hz, 2H), 7.68 (s, 2H), 7.45-7.40 (m, 2H), 7.39-7.35 (m, 4H), 2.20 (t, J= 8.1 Hz, 8H), 1.79 (dt, J= 18.8, 11.2 Hz, 8H), 0.95 (q, J= 7.2 Hz, 8H) ppm.19F NMR (376 MHz, CDCh) 6: -80.93, -114.67, -122.13, -122.91, -123.80, -126.28 ppm. See FIG. 32A.

[0230] Perfluoroalkylated IndenoFluorene 7 (200 mg, 0.095 mmol) was dissolved in CHCh (10 mL). Then, a teaspoon of I2 was added to the solution mixture followed by the addition of Br2 (40 pL, 0.764 mmol) and the mixture was stirred at 60 °C for 6 h. After this time, another teaspoon of I2 was added followed by the addition of Br2 (40 pL, 0.764 mmol) and the mixture was stirred at 60 °C for 16 h. Next day, the resulting mixture was washed with an aqueous solution of Na2S2O3, and the aqueous layer was extracted with large quantities of hot CHCh (at least three times). The combined organic phases were washed with water, brine and then solvent was removed under reduced pressure. The product was purified by several washed with EtOH to afford 8 (116 mg, 54 %) as a light-yellow solid. ’ H NMR (400 MHz, CDCh) 8: 7.67 (d, J= 8.1 Hz, 2H), 7.63 (s, 2H), 7.61-7.53 (m, 2H), 7.51 (d, J= 1.7 Hz, 2H), 2.17 (t, J= 8.4 Hz, 8H), 1.83 (t, J= 18.5 Hz, 8H), 1.01-0.80 (m, 8H) ppm.19F NMR (376 MHz, CDCh) 6 -80.98, - 114.79, -122.17, -122.93, -123.79, -126.31 ppm. See FIG. 32B. 5,10-Dihydroindeno[2,l-a]indene (9, 150 mg, 0.73 mmol), 3 -(Perfluorooctyl) propyl iodide (1.89 g, 3.23 mmol), tetrabutylammonium bromide (118 mg, 0.37 mmol) were dissolved in DMSO (10 mL) and heated to 90 °C. Subsequently, an aqueous solution of potassium hydroxide (1.65 g, 29.3 mmol, in 5.0 mL H2O) was added drop wise to the reaction flask over a period of 20 minutes. The reaction mixture was stirred at 90 °C for 24 h under argon atmosphere. Next day, EtOAc was added to the mixture without cooling down to r.t. and the organic phase was washed with water, brine, and dried over anhydrous sodium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by consecutive washes with EtOH, CH2CI2 and toluene, to afford 10 (310 mg, 21 %) as a pale white solid.!H NMR (400 MHz, CD2CI2) 6: 7.42-7.35 (m, 6H), 7.31 (td, J= 7.1, 1.8 Hz, 2H), 2.34-2.14 (m, 8H), 1.98-1.82 (m, 8H), 1.22-1.11 (m, 4H), 1.04-0.86 (m, 4H) ppm.19F NMR (376 MHz, CD2CI2) 6: -81.30, -114.72, -122.74, -123.03, -123.97, -126.50 ppm. See FIG. 32C.

[0231] Perfluoroalkylated Indenolndene 10 (310 mg, 0.152 mmol) was dissolved in CHCh (12.5 mL). Then, a teaspoon of I2 was added to the solution mixture followed by the addition of Br2 (94 pL, 1.82 mmol) and the mixture was stirred at 60 °C for 24 h. Then, the reaction was allowed to cool down to r.t., and subsequently the solvent was removed under reduced pressure. The crude product was washed with EtOH and recrystallized from CHCh obtaining 11 (288 mg, 86 %) as a white solid.1H NMR (400 MHz, CDCh) 6: 7.56-7.47 (m, 4H), 7.20 (d, J = 7.9 Hz, 2H), 2.30-2.06 (m, 8H), 1.97- 1.81 (m, 8H), 1.17-1.08 (m, 4H), 0.99-0.89 (m, 8H) ppm.19F NMR (376 MHz, CDCh) 5: -80.92, -114.76, -122.12, -122.92, -123.67, -126.27 ppm. See FIG. 32D.

[0232] Perfluoroalkylated dibromolndenolndene 11 (200 mg, 0.091 mmol), ILPi (69.2 mg, 0.272 mmol), KOAc (53.6 mg, 0.546 mmol) and Pd(dppf)Ch (13.3 mg, 0.018 mmol) were dissolved in dioxane (8 mL). The mixture was heated at 110 °C (reflux) for 48 h under argon atmosphere. Then, water was added to the mixture and the precipitate was filtered. The crude product was dissolved in hot CHCh and filtered through a silica plug with hot CHCh and hot AcOEt. The solvent was removed under reduced pressure and the product was recrystallized from acetone obtaining 12 (110 mg, 53 %) as a pale white solid. ’ H NMR (400 MHz, CDCh) 8: 7.85 (d, J= 7.4 Hz, 2H), 7.75 (s, 2H), 7.36 (d, J= 7.4 Hz, 2H), 2.31-2.17 (m, 8H), 1.89-1.79 (m, 8H), 1.19-1.03 (m, 4H), 0.98-0.84 (m, 4H) ppm. See FIG. 32E.

[0233] 477-Cyclopenta[2, 1-Z 3, 4-Z ] dithiophene (13, 0.335 g, 1.88 mmol) and 3- (perfluorooctyl)propyl iodide (2.44 g, 4.14 mmol) were dissolved in DMSO (5 mL). Then, an aqueous solution of potassium hydroxide (2.11 g, 37.6 mmol, in 2 mL H2O) and tetrabutylammonium bromide (0.133 g, 0.41 mmol) were added to the reaction flask. The mixture was stirred at 90 °C for 24 h under argon atmosphere. Then, the mixture was allowed to cool down to r.t., poured into water and extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiCL, Hexanes) obtaining 14 (1.88 g, 43 %) as a light-yellow solid. ’ H NMR (400 MHz, CDCh) 6: 7.22 (d, J= 4.9 Hz, 2H), 6.93 (d, J= 4.9 Hz, 2H), 2.03-1.95 (m, 4H), 1.85 (td, J= 18.7, 18.3, 9.2 Hz, 4H), 1.30-1.16 (m, 4H) ppm.19F NMR (376 MHz, CDCI3) 6: - 80.75, -114.34, -121.76, -121.96, -122.71, -123.70, -126.09 ppm. See FIG. 32F.

[0234] / V- Bro mo succinimide (250 mg, 1.40 mmol) was added to a solution of 14 (750 mg, 0.683 mmol) in dry THF (7 mL) at 0 °C. After the addition, the mixture was stirred at r.t. for 6 h under argon atmosphere. Then, water was added to the reaction mixture, and the product was extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiO2, Hexanes) obtaining 15 (780 mg, 91 %) as a yellow solid. ’ H NMR (400 MHz, CDCI3) 6: 6.94 (s, 2H), 2.01-1.80 (m, 8H), 1.22 (qd, J= 12.0, 10.2, 6.3 Hz, 4H) ppm.19F NMR (376 MHz, CDCI3) 6: -80.75, -114.24, - 121.72, -121.92, -122.68, -123.70, -126.08 ppm. See FIG. 32G.

[0235] Compound 15 (400 mg, 0.320 mmol), B2PHI2 (203 mg, 0.800 mmol), KOAc (189 mg, 1.92 mmol) and Pd(dppf)Ch (23.5 mg, 0.032 mmol) were dissolved in dioxane (5 mL). The mixture was heated at 90 °C for 48 h under argon atmosphere. Then, water was added to the reaction mixture, and the product was extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiO2, CHCh / hexanes, from 20 / 80 to CHCh / hexanes / acetone, 20 / 75 / 5) obtaining 16 (371 mg, 91 %) as a dark solid.JH NMR (400 MHz, CDCh) 6: 7.41 (s, 2H), 2.00-1.93 (m, 4H), 1.91-1.76 (m, 4H), 1.26 (s, 12H), 1.23-1.15 (m, 4H) ppm.19F NMR (376 MHz, CDCh) 5: -80.75, -114.31, -121.75, -121.95, -122.69, -123.73, -126.09 ppm. See FIG. 32H.

[0236] 2,7-dibromofluorene (17, 0.692 g, 2.14 mmol) and 3-(perfluorobutyl)propyl iodide (1.83 g, 4.71 mmol), tetrabutylammonium bromide (70 mg, 0.214 mmol) were dissolved in DMSO (15 mL) and heated to 90 °C. Subsequently, an aqueous solution of potassium hydroxide (2.40 g, 42.8 mmol, in 5 mL H2O) was added dropwise to the reaction flask and the reaction mixture was stirred at 90 °C for 24 h under argon atmosphere. Then, the mixture was allowed to cool down to r.t., poured into water and extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiCL, Hexanes) obtaining 18 (1.21 g, 67 %) as a colorless oil. ’ H NMR (400 MHz, CDCh) 6: 7.62-7.49 (m, 4H), 7.48-7.42 (m, 2H), 2.12-2.00 (m, 4H), 1.84 (tt, J= 18.4, 7.8 Hz, 4H), 0.91 (tt, J= 10.6, 6.3 Hz, 4H) ppm. See FIG. 321.

[0237] Compound 18 (500 mg, 0.592 mmol), B2PHI2 (376 mg, 1.48 mmol), KO Ac (349 mg, 3.55 mmol) and Pd(dppf)Ch (48 mg, 0.0592 mmol) were dissolved in dioxane (10 mL). The mixture was heated at 90 °C for 24 h under argon atmosphere. Then, water was added to the reaction mixture, and the product was extracted three times with ethyl acetate. The combined organic phases were washed with water, brine and dried over anhydrous magnesium sulfate. The solution was filtered, and the solvent was removed under reduced pressure. The product was purified by column chromatography (SiO2, EtOAc / hexanes, 5 / 95) obtaining 19 (422 mg, 76 %) as a white solid.1H NMR (400 MHz, CDCh) 8: 7.85 (dd, J= 7.5, 1.0 Hz, 2H), 7.80-7.65 (m, 4H), 2.20-2.07 (m, 4H), 1.75 (tt, J= 18.3, 7.8 Hz, 4H), 1.39 (s, 24H), 0.92-.082 (m, 4H) ppm. See FIG. 32J.

[0238] General procedure for polymer synthesis

[0239] Sonogashira polymerization (Procedure A)'. A degassed solution of diisopropylamine / toluene (2:3, 0.015 M) was added to a Schlenk flask containing dialkyne pentiptycene, dihaloarenes, copper (I) iodide, and tetrakis(triphenylphosphine)palladium (0). The flask was deoxygenated by three freeze-pump-thaw cycles and flushed with argon. The reaction mixture was stirred at 80 °C for 72 hours. After cooling down to RT, the polymer precipitates in the solvent mixture. Then, tetrahydrofuran was added to the reaction mixture to dissolve the polymer which was precipitated into methanol twice and washed with hot methanol and acetone.

[0240] Suzuki polymerization (Procedure B): A degassed benzotrifluoride solution (0.08 M) was added to a Schlenk flask containing dihaloarenes, boronic esters, and tetrakis(triphenylphosphine)palladium (0). Then, an aqueous solution of tetraethylammonium hydroxide (35 wt. % in water, 0.08 M) was added. The flask was deoxygenated by three freeze-pump-thaw cycles and flushed with argon. The reaction mixture was stirred at 90 °C for 48 hours. After cooling down to RT, the mixture was precipitated into methanol. The solid was re-dissolved in benzotrifluoride and precipitated in methanol three times.

[0241] PPE-Py_0.5-0.5 was prepared according to procedure A. Yellow solid (71 %).JH NMR (400 MHz, CDCh) 6: 9.32-9.24 (m, 1H), 8.37-8.30 (m, 1H), 8.07-8.00 (m, 1H), 7.73-7.37 (m, 22H), 7.18-6.90 (m, 12H), 6.24-5.83 (m, 6H), 4.64-4.47 (m, 4H), 2.62- 2.47 (m, 8H) ppm.19F NMR (376 MHz, CDCh) 6: -80.80, -113.89, -121.60, -121.90, - 122.70, -123.15, -126.12 ppm. GPC (THF): Mn= 33.9 kDa, £> = 1.81. See FIG. 33A.

[0242] PF-Py_0.5-0.5 was prepared according to procedure B. Orange-greenish solid (89 %) with low solubility in CHCh and THF. ’ H NMR (400 MHz, CDCh) 8: 9.1-9.05 (m, 0.58H), 8.27-7.44 (m, 15H), 2.36-2.21 (m, 6H), 1.97-1.81 (s, 6H), 1.19-0.99 (s, 6H) ppm.19F NMR (376 MHz, CDCh) 6: -80.82, -114.38, -121.68, -122.03, -122.78, - 123.78, -126.21 ppm. GPC (THF): Mn= 4.78 kDa, £> = 1.12. See FIG. 33B.

[0243] PF-3,5-Py was prepared according to procedure B. Green solid (87 %) with low solubility in THF. ’ H NMR (400 MHz, CDCh) 6: 8.98-8.93 (m, 0.12H), 7.98-7.32 (m, 7H), 2.35-2.12 (m, 4H), 2.00-1.75 (m, 4H), 1.33-1.06 (m, 4H) ppm.19F NMR (376 MHz, CDCh) 6: -81.08, -82.18, -114.52, -122.23, -122.98, -124.12, -126.41 ppm. GPC (THF): Mn= 4.3 kDa, £> = 1.19. See FIG. 33C.

[0244] PF-2,6-Py was prepared according to procedure B. Dark green solid (83 %) with low solubility in THF. ’H NMR (400 MHz, CDCh) 6: 7.98-7.32 (m, 7H), 2.31-2.16 (m, 4H), 2.02-1.74 (m, 4H), 1.32-1.16 (m, 4H) ppm.19F NMR (376 MHz, CDCh) 6: -81.14, -82.22, -114.51, -122.04, -122.26, -123.04, -124.13, -126.44 ppm. GPC (THF): Mn= 5.4 kDa, £> = 1.17. See FIG. 33D. PF-PF-Py was prepared according to procedure B. Green solid (66 %).!H NMR (400 MHz, CDCh) 6: 9.12-9.05 (m, 0.5H), 8.24-7.49 (m, 8H), 2.39-2.09 (m, 4H), 2.01-1.80 (m, 4H), 1.21-1.04 (m, 10H), 0.88-0.71 (m, 4H) ppm.19F NMR (376 MHz, CDCh) 6: -80.95, -114.51, -122.08, -122.87, -123.92, -126.30, -124.12 ppm. GPC (THF): Mn= 16.0 kDa, £> = 1.41. See FIG. 33E.

[0245] PF-3,5-Py was prepared according to procedure B. Green solid (74 %). Insoluble in CHCh and THF. See FIG. 33F.

[0246] PIF-PF-Py was prepared according to procedure B. Dark green solid (72 %) with low solubility in CHCh and THF.1H NMR (400 MHz, CDCh)) 8: 9.11-9.06 (m, 0.56H), 8.30-7.33 (m, 12.62H), 2.38-2.16 (m, 8H), 1.98-1.78 (m, 8H), 1.20-1.02 (m, 8H) ppm.19F NMR (376 MHz, CDCh) 6: -80.91, -81.07, -114.35, -122.08, -122.82, -123.91, -126.24 ppm. GPC (THF): Mn= 8.03 kDa, £> = 1.32. See FIG. 33G.

[0247] PH-Py was prepared according to procedure B. Green solid (86 %) with low solubility in CHCh and insoluble in THF.1H NMR (400 MHz, CDCh) 6: 9.08-9.03 (m, 0.1H), 7.79-7.36 (m, 8H), 2.50-2.09 (m, 8H), 1.90 (m, 8H), 1.29 (m, 4H), 1.09 (m, 8H) ppm.19F NMR (376 MHz, CDCh) 6: -81.11, -114.79, -122.20, -123.10, -123.63, - 124.01, -126.45, -126.56 ppm. See FIG. 33H.

[0248] C4PF-C8PF-Py was prepared according to procedure B. Light green solid (71 %). ’ H NMR (400 MHz, CDCh) 6: 9.09 (s, 0.31H), 8.36-7.33 (m, 7.33H), 2.38-2.13 (m, 4H), 2.00-1.81 (m, 4H), 1.44-0.90 (m, 4H) ppm.19F NMR (376 MHz, CDCh) 6: -80.91, -81.30, -81.44, -114.41, -114.69, -121.89, -122.07, -122.86, -123.96, -124.88, -125.00, - 126.23, -126.33 ppm. GPC (THF): Mn= 9.73 kDa, £> = 1.72. See FIG. 331.

[0249] EXAMPLE 6

[0250] The following example describes materials and methods used to functionalize polymer supports with sensing materials and their sensing properties.

[0251] Materials

[0252] The tubing used for functionalization and sensing experiments has a size of 1 / 16 inches Inside Diameter and 1 / 8 inches Outside Diameter. The type of tubing and where it was purchased are indicated as follows: PFA tubing (Zeus), Silicone / Polyethylene tubing (Amazon, B0BWJ3S5NM), LDPE (IE Rents), Silicone (Amazon, ANPTGHT). Silica Spheres (60 A, 20-45 pm) were purchased from Sorbent Technologies. Glass slides (Plain selected, pre-cleaned 25 x 75 x 1 mm) were purchased from VWR.

[0253] Tubing functionalization

[0254] PFA tubing: PFA tubing was heated at 120 °C in an oil bath, and it was filled with a hot solution of the polymer in anisole (1 mg / mL). After 10 minutes of heating at 120 °C, the tubing (filled with the polymer solution) was allowed to cool over the course of 1 hour. Finally, the solution was drained, the tubing was rinsed with MeOH and dried under reduced pressure for 16 hours.

[0255] PTFE tubing: PTFE tubing was heated at 120 °C in an oil bath, and it was filled with a hot solution of the polymer in anisole (1 mg / mL). After 10 minutes of heating at 120 °C, the tubing (filled with the polymer solution) was allowed to cool over the course of 1 hour. Finally, the solution was drained, the tubing was rinsed with MeOH and dried under reduced pressure for 16 hours.

[0256] Both PFA and PTFE tubing can be functionalized with different solvents such as benzotrifluoride, o-dichlorobenzene and THF from r.t. to 120 °C.

[0257] LDPE tubing: Surface modification of LDPE tubing was needed to efficiently coat the polymers. LDPE tubing was heated at 100 °C in an oil bath, and it was filled with a 30% H2O2 solution for 15 min. While it was still hot, the solution was drained, the tubing was rinsed with water, ethanol and died under reduced pressure for 16 hours. For the prefunctionalization, a fluorinated siloxane solution was prepared. To a 2 wt.% solution of a fluorous silane (1H,1H,2H,2H-Perfluorodecyltriethoxysilane or Nonafluorohexyltriethoxysilane) in THF / water (95 / 5), acetic acid was added, and the pH was adjusted to 5. Then, the LDPE tubing was filled with the siloxane solution and keep it for 2 h and 30 min at r.t.. Then, the solution was drained, and the tubing was rinsed with MeOH, and dried with nitrogen steam. Finally, the tubing was filled with a polymer solution (1 mg / mL) in benzotrifluoride. After 30 min at r.t., the solution was drained, the tubing was rinsed with MeOH and dried under reduced pressure for 16 hours.

[0258] Silica Spheres functionalization

[0259] In a round bottom flask, 14.4 mL of ethanol, 1 mL of water and 25 mL of ammonium hydroxide were stirred for 10 min. This was followed by the addition of 1.6 g of the silica spheres and after 30 min, the fluorous silane was added (1.2 mL). The mixture was then stirred overnight for 18 h at r.t. Then, the mixture was centrifuged and washed three times with ethanol for the complete removal of reactants. The silica spheres were dried under reduced pressure for 6 hours.

[0260] Later, 100 mg of the silica spheres were added to 2 mL of the polymer solution (1 mg / mL) in benzo trifluoride. After 2 hours, the spheres were filtered, rinsed with MeOH, and dried under reduced pressure for 16 h.

[0261] Silica Nanoparticle (NP) Synthesis and Functionalization

[0262] In a 100 mL round bottom flask, 14.4 mL of ethanol, 1 mL of ultrapure water and 25 mL of ammonium hydroxide were stirred at 400 rpm for 10 min. This was followed by the addition of 1 mL TEOS ((EtO)4Si) diluted in 4 mL of ethanol. After 30 min, 0.5 mL of TEOS in 2 mL of ethanol dilution was added. Another 5 min later, the respective modifier silane molecule was added in molar ratio of 3:4 with respect to the second addition of TEOS (1.14 mL RF silane). The mixture was then magnetically stirred overnight for 18 h at room temperature. After which the mixture was centrifuged and washed three times with ethanol for the complete removal of reactants. The silica NPs were dried in a vacuum oven at r.t. for 6 h.

[0263] 100 mg of the Silica NPs were added to 2 mL of a 0.5 mg / mL solution of polymer in trifluorotoluene and keep them there for 2 h. Then, they were filtered and washed with EtOH.

[0264] Glass slides functionalization

[0265] Glass slides were functionalized following LDPE tubing as well as silica spheres procedures.

[0266] Sensing experiments (PFAS in water samples)

[0267] Peristaltic pumps are smoothflow pumps from Tacmina corporation (Model: Ql- 5-6R-UP-ES). The flow used in sensing experiments was 5 mL / min. PFAS samples were stored in polypropylene containers, and silicone / PE tubing was used to recirculate the solutions. Adaptors to connect the peristaltic pump to the tubing were purchased from Cole Parmer such as Standard Knurl and peel connector unions.

[0268] FIGS. 34A-34B show emission spectra and a corresponding PFOA calibration curve (continuous flow (5 mL / min) for 1 hour). The dotted arrow in FIG. 34A shows a general trend from 10 ppb to 0 ppb. FIGS. 35A-35B show emission spectra and a corresponding PFOS calibration curve (continuous flow (5 mL / min) for 1 hour). The dotted arrow in FIG. 35A shows a general trend from 10 ppb to 0 ppb. FIGS. 36A-36B show emission spectra and a corresponding HFPO-DA (GenX) calibration curve (continuous flow (5 mL / min) for 1 hour). The dotted arrow in FIG. 36A shows a general trend from 25 ppb to 0 ppb. FIGS. 37A-37B show emission spectra and the corresponding pH influence in the polymer activation.

[0269] 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 as examples only. While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill 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 of the 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 depend upon the specific application or applications for which the teachings of the present invention is / 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. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, 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, if such features, systems, articles, materials, and / or methods are not mutually inconsistent, is included within the scope of the present invention.

[0270] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0271] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction 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); etc.

[0272] As used herein in the specification 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., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of 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.

[0273] As used herein in the specification and in the claims, the phrase “at least one,” in reference to 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 not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (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.

[0274] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like 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 United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMSWhat is claimed is:

1. An article configured to sense a fluoroalkyl substance, comprising: a polymer support comprising fluorine at a surface of the polymer support, wherein an amount of fluorine at the surface of the polymer support is greater than or equal to 10 weight percent (wt.%) versus a total weight of the polymer support; and a sensing material, wherein the polymer support is at least partially functionalized with the sensing material.

2. The article of claim 1, wherein the amount of fluorine at the surface of the polymer support is greater than or equal to 30 wt.% versus the total weight of the polymer support.

3. The article of any one of claims 1-2, wherein the fluoroalkyl substance is a perfluoroalkyl substance and / or a polyfluoroalkyl substance.

4. The article of any one of claims 1-3, wherein the sensing material is a fluorescent material with a quantum yield greater than or equal to 30%.

5. The article of any one of claims 1-4, wherein the polymer support comprises a perfluoroalkoxy alkane (PFA).

6. The article of any one of claims 1-5, wherein the amount of fluorine at the surface of the polymer support is greater than or equal to 10 wt.% versus a total weight of surface material.

7. The article of claim 6, wherein the amount of fluorine at the surface of the polymer support is greater than or equal to 30 wt.% versus the total weight of the surface material.

8. The article of any one of claims 1-7, wherein the sensing material comprises fluorine in an amount greater than or equal to 10 wt.% versus a total weight of the sensing material.

9. The article of claim 8, wherein the sensing material comprises fluorine in an amount greater than or equal to 30 wt.% versus the total weight of the sensing material.

10. The article of any one of claims 8-9, wherein the sensing material comprises fluorine in an amount greater than or equal to 45 wt.% versus the total weight of the sensing material.

11. The article of any one of claims 1-10, wherein the sensing material is configured to absorb the fluoroalkyl substance.

12. The article of any one of claims 1-11, wherein the sensing material comprises at least one chromophore that displays a change in electromagnetic radiation emission in response to a presence of the fluoroalkyl substance.

13. The article of claim 12, wherein the sensing material comprises a nitrogencontaining heterocycle that is configured to interact with the fluoroalkyl substance such that the at least one chromophore displays the change in electromagnetic radiation emission.

14. The article of claim 13, wherein the fluoroalkyl substance is configured to protonate the nitrogen-containing heterocycle.

15. The article of claim 12, wherein the presence of the fluoroalkyl substance changes an efficiency of an energy transfer of the at least one chromophore.

16. The article of any one of claims 1-15, wherein the sensing material is configured to sense the fluoroalkyl substance in water at a concentration less than or equal to 10 parts per trillion (ppt).

17. The article of any one of claims 1-16, wherein the polymer support comprises a material having a flexural modulus less than or equal to 600 MPa such that the polymer support is flexible.

18. The article of any one of claims 1-17, wherein the polymer support comprises a material that is substantially transparent to: (i) electromagnetic radiation used to excite the sensing material; and (ii) electromagnetic radiation emitted from the sensing material.

19. The article of any one of claims 1-18, wherein the polymer support is in the form of a tube and the sensing material is functionalized on an inner surface of the tube.

20. The article of any one of claims 1-19, wherein the polymer support is at least partially porous.

21. The article of any one of claims 1-18, wherein the polymer support comprises a particle.

22. The article of claim 21, wherein the particle is substantially spherical.

23. The article of any one of claims 21-22, wherein the particle is a nanoparticle.

24. The article of any one of claims 1-23, wherein the article is part of a filtration system.

25. The article of any one of claims 1-24, wherein the polymer support comprises modified cellulose.

26. The article of any one of claims 1-25, wherein the polymer support comprises a poly siloxane.

27. The article of any one of claims 1-26, wherein the polymer support is deposited on a surface of a substrate.

28. The article of claim 27, wherein the substrate comprises glass.

29. A method of detecting and / or determining a fluoroalkyl substance, comprising: exposing an article to a fluid suspected of comprising the fluoroalkyl substance, wherein the article comprises: a polymer support comprising fluorine in an amount greater than or equal to 10 weight percent (wt.%) versus a total weight of the polymer support; and a sensing material, wherein the polymer support is at least partially functionalized with the sensing material; and detecting a change in electromagnetic radiation emission of the sensing material.

30. The method of claim 29, wherein the amount of fluorine at a surface of the polymer support is greater than or 30 wt.% versus the total weight of the polymer support.

31. The method of any one of claims 29-30, wherein the fluoroalkyl substance is a perfluoroalkyl substance and / or a polyfluoroalkyl substance.

32. The method of any one of claims 29-31, wherein the method of detecting and / or determining the fluoroalkyl substance comprises detecting a presence of and / or determining an amount of the fluoroalkyl substance, if present, based on the change in electromagnetic radiation emission of the sensing material.

33. The method of any one of claims 29-32, wherein the polymer support is in the form of a tube and the sensing material is functionalized on an inner surface of the tube, and wherein the exposing comprises flowing the fluid through the tube such that the fluid is exposed to the sensing material functionalized on the inner surface of the tube.

34. The method of any one of claims 29-33, wherein the detecting comprises continuously detecting the change in electromagnetic radiation emission of the sensing material.

35. The method of any one of claims 33-34, wherein the detecting comprises detecting the change in electromagnetic radiation emission of the sensing material as a function of time and / or as a function of a position within the tube.

36. The method of any one of claims 31-35, wherein the detecting reveals information about a composition of the fluoroalkyl substance, if present.

37. The method of any of claims 31-36, wherein the fluid comprises at least one liquid.

38. The method of claim 37, wherein the fluid comprises water.

39. The method of claim 38, wherein the water is from an industrial waste stream.

40. The method of claim 38, wherein the water is from a landfill leachate.

41. The method of claim 38, wherein the water is from a preconcentrator system.

42. The method of claim 38, wherein the water is from a well.

43. The method of claim 38, wherein the water is from food.

44. The method of any one of claims 37-43, wherein the fluid comprises at least one organic solvent.

45. The method of any one of claims 29-37, wherein the fluid comprises water and at least one organic solvent.

46. The method of any one of claims 29-37, wherein the fluid comprises at least one gas.

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