Nanomaterial-Based Fluorescent Sensors and Related Methods

Abstract

The sensors (4) can be used to detect the concentration of an analyte, such as an electrolyte and / or a blood gas. In some models, these sensors may include a matrix material, a nanoparticle (2) associated with the matrix material, and a signaling molecule (10, 12, 14, 16) associated with the nanoparticle. In some cases, the signaling molecule may exhibit a fluorescence emission intensity (20, 22, 24, 26) as a function of the analyte concentration. Abbreviated figure: Fig. 2.

Description

Title of the invention: NANOMATERIAL-BASED FLUORESCENT SENSORS AND RELATED METHODS Technical field

[0001] This description relates to sensors used to detect and measure analyte concentrations, and more particularly to fluorescent nanomaterial sensors used to detect, measure, and control biological analytes. General Information

[0002] Monitoring biological analytes such as pH, blood gases, electrolytes, and metabolites has been a primary method for assessing individuals' overall health and the status of their bodily functions, particularly in intensive care settings. For example, dedicated analyzers are used in patient-close testing environments to enable continuous, real-time measurement and detection of blood analytes in critical care situations. Measuring blood analytes provides valuable information regarding an individual's oxygenation status, gas exchange, acid-base homeostasis, and ventilation. Although various biological analyte sensor technologies have been developed, improvements in design, functionality, and accuracy are continually being pursued. Summary

[0003] The present description describes sensors used to detect and measure analyte concentrations, and more particularly fluorescent nanomaterial sensors used to detect, measure and monitor blood gas analytes.

[0004] In one aspect, this disclosure relates to a sensor for detecting an analyte concentration. The sensor comprises a matrix material, a nanoparticle associated with the matrix material, and a signaling molecule associated with the nanoparticle. The nanoparticle or the signaling molecule exhibits a fluorescence emission intensity that is a function of the analyte concentration.

[0005] Such a sensor may optionally include one or more of the following features. The analyte may be potassium, oxygen, carbon dioxide, a hydrogen ion, or any combination thereof. The matrix material may be a hydrogel matrix. The matrix material may be permeable to the analyte. The nanoparticle may be a polymer nanoparticle. The nanoparticle may be a quantum dot. The quantum dot may exhibit a distinct emission wavelength. The signaling molecule may modify the intensity of the fluorescence emission from the quantum dot as a function of of the analyte concentration. The signaling molecule can decrease or increase the fluorescence emission intensity of the nanoparticle in the absence of the analyte. The signaling molecule can increase or decrease the fluorescence emission intensity of the nanoparticle in the presence of the analyte. The signaling molecule can be a fluorophore. The signaling molecule can be a non-fluorophore. The signaling molecule can be hydroxypyrenetrisulfonic acid, benzo[ghi]perylene, a coumarocryptand, or any combination thereof. The sensor can be optically coupled to a measuring device. The sensor can be a ratiometric sensor. The nanoparticle or the signaling molecule can exhibit a fluorescence emission intensity that is a function of temperature.

[0006] According to another aspect, this description relates to a sensor for detecting an analyte concentration comprising a matrix material, a donor chromophore, and an acceptor chromophore. The donor chromophore can transfer energy to the acceptor chromophore in the presence of the analyte, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating the presence of the analyte.

[0007] Such a sensor may optionally include one or more of the following features. The analyte may be potassium, oxygen, carbon dioxide, a hydrogen ion, or any combination thereof. The matrix material may be a hydrogel matrix. The matrix material may be permeable to the analyte. The donor chromophore or the acceptor chromophore may be a nanoparticle. The nanoparticle may be a polymer nanoparticle. The nanoparticle may be a quantum dot. The acceptor chromophore or the donor chromophore may be a fluorescent dye. The sensor may be optically coupled to a measuring device. The sensor may be a ratiometric sensor. The donor chromophore may transfer energy to the acceptor chromophore as a function of temperature, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating a temperature change.

[0008] According to yet another aspect, this description relates to a method for detecting the concentration of an analyte in a fluid. The method consists of providing one or more sensors that comprise a matrix material, a nanoparticle associated with the matrix material, and a signaling molecule associated with the nanoparticle. The signaling molecule or the nanoparticle may exhibit a fluorescence emission intensity that depends on the analyte concentration. The method may also include exposing one or more sensors to the fluid. The method may also include measuring the intensity of the fluorescence emission. The method may also include analyte detection based on the measured fluorescence intensity.

[0009] Such a method may optionally include one or more of the following features. The fluid may be a biological fluid. The biological fluid may be blood.

[0010] Specific modes of the object described in this document can be implemented to achieve one or more of the following advantages. In some cases, the sensors described herein may have increased stability, allowing use beyond approximately 6 hours. In some cases, this increased stability of the sensors provided herein may be beneficial in critical care situations such as surgery, where it would be preferable to avoid having to recalibrate, reprime, and / or exchange a sensor during the operation, as continuous monitoring of a patient's blood analytes is vital. Furthermore, the time required by the clinician to exchange, recalibrate, or reprime a sensor may be reduced. This, in turn, may lead to a reduction in the risk of clinician error during a calibration and / or measurement step using the sensor.Furthermore, the sensors provided here may have reduced interference and / or noise and, consequently, improved accuracy. A reduction in interference and / or noise can lead to improvements in the sensitivity, specificity, precision, and / or accuracy of the sensor measurements. Additionally, in some versions, the sensors in this disclosure may use a single probe (e.g., a nanoparticle) to detect and measure multiple analytes. Such multi-analyte sensors with a single probe can improve manufacturing and quality control. For example, a multi-analyte sensor using multiple probes to detect two or more analytes is typically manufactured using at least two fabrication processes, one for each probe.The sensors supplied here can be manufactured in a single process, which reduces the overall manufacturing time and quality control activities (e.g., quality inspections to ensure proper sensor performance).

[0011] Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as that commonly understood by specialists in the art to which this invention relates. Although methods and materials similar or equivalent to those described in this document may be used to carry out the invention, appropriate methods and materials are described herein. All publications, patent applications, patents, and other references mentioned in this document are incorporated by reference in their entirety. In case of conflict, this specification shall prevail. including the definitions, shall prevail. Furthermore, the materials, methods, and examples are provided for illustrative purposes only and are not intended to be exhaustive.

[0012] The use of the term "approximately," as used herein, refers to an amount that is close to the stated amount by approximately 10%, 5%, or 1%, including increments thereof. For example, "approximately" may mean a range including the particular value and extending from 10% below that particular value to 10% above that particular value.

[0013] Details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will appear in the description and drawings, as well as in the claims. Description of the drawings

[0014] [Fig.1] Fig.1 is a schematic representation of a sensor according to certain embodiments provided herein.

[0015] [Fig.2] Figure [Fig.2] schematically represents an excitation process of a sensor according to certain embodiments provided herein.

[0016] The corresponding reference symbols in the different drawings indicate corresponding elements. Detailed description

[0017] The present description describes the sensors used to detect and measure analyte concentrations, and more particularly the fluorescent nanomaterial sensors used to detect, measure and monitor blood gas analytes.

[0018] With reference to [Fig. 1], an example of a sensor 4 for detecting an analyte concentration is schematically represented. The sensor 4 comprises a matrix material. The sensor 4 further comprises a cover layer 6 and a chemical layer 8, as shown in [Fig. 1]. The cover layer 6 may be in fluid contact with the medium containing the analyte to be measured or be exposed to it in some other way. The cover layer 6 may comprise the matrix material. In some cases, the matrix material is permeable to the analyte to be measured. In some examples, the matrix material is insoluble in the medium to be monitored by the sensor 4. In some examples, the matrix material is a hydrogel matrix. The term "hydrogel," as used here, is defined as a three-dimensional macromolecular material comprising a network structure. In some cases, the hydrogel contains a hydrophobic agent.In some cases, the matrix material is a polymer material. Non-limiting examples of polymer materials include ion-permeable cellulosic materials, high molecular weight or cross-linked polyvinyl alcohol (PVA), dextran, and dextran. Crosslinked polyurethanes, quaternized polystyrenes, sulfonated polystyrenes, polyacrylamides, polyhydroxyalkyl acrylates, polyvinylpyrrolidones, hydrophilic polyamides, polyesters, and any combination thereof. In some examples, the matrix material is cellulose. In some examples, the matrix material is a cellulose hydrogel. In some cases, the matrix material is coated onto a substrate. In some embodiments, the substrate is disc-shaped. In some cases, the matrix material is disc-shaped. In some examples, the matrix material is freeze-dried. In some cases, the matrix material is produced by a coating or similar process. Manufacturing the sensor for the development process using a coating process would significantly reduce the complexity, variability, and production of manufacturing compared to conventional manufacturing processes.

[0019] The cover layer 6 comprises an opacifying layer that optically isolates a nanoparticle and / or a signaling molecule in the chemical layer 8. The cover layer 6 may comprise an optically opaque agent. Non-limiting examples of optically opaque agents include carbon black, carbon-based opacities, ferric oxide, and metallic phthalocyanines. In some cases, the optically opaque agent is dispersed substantially uniformly within the polymer in an amount sufficient to achieve the desired degree of opacity to provide the required optical isolation. Carbon black is a particularly useful opacity agent. The cover layer 6 may also be a coating on the chemical layer 8.For example, the overcoat 6 may be an ink coating on the chemical layer 8 applied using various techniques, such as, but not limited to, inkjet or ink halftone techniques. In some cases, the overcoat 6 may also be a black membrane associated with the chemical layer 8. In some examples, the overcoat layer 6 comprises carbon black dispersed in an epoxy-crosslinked dextran matrix.

[0020] As shown in [Fig. 1], the chemical layer 8 comprises one or more nanoparticles 2. The chemical layer 8 is the sensing layer of the sensor 4. In other words, the chemical layer 8 comprises the sensing agents that can detect the concentration of an analyte of interest. In this example, the sensing agents are nanoparticles 2 and a signaling molecule. The nanoparticle 2 is associated with the matrix material. For example, the nanoparticle 2 may be incorporated into or trapped within the matrix material. In some cases, the nanoparticle 2 may be dissolved or dispersed within the matrix material. In yet another example, the nanoparticle 2 may be adsorbed onto an inner and / or outer surface of the matrix material. In other cases, the nanoparticle 2 may The nanoparticles can be reversibly or irreversibly coupled to the matrix material. Nanoparticles 2 can be covalently coupled to the matrix material. Examples of conjugating chemicals that can be used to couple nanoparticles 2 to the matrix material include, but are not limited to, carbodiimides, N-hydroxysuccinimide esters, imidoesters, maleimidies, haloacetyls, pyridyl disulfides, hydrazides, alkoxyamines, aryl azides, diazirines, Staudinger reagent pairs, or any combination thereof. The matrix material for chemical layer 8 can be the same as the matrix materials described previously.

[0021] Nanoparticle 2 can have a diameter of approximately 1 to 999 nanometers (nm). In some cases, nanoparticle 2 is a metallic nanocluster, a carbon nanotube, a nanodiamine, a carbon nanodot, or any combination thereof. In other cases, nanoparticle 2 is a quantum dot. The structure of the quantum dot may consist of a core and a shell. Quantum dots (QDs) are colloidal, semiconducting, and highly luminescent nanocrystals, typically ranging in diameter from approximately 1 to 10 nm. Excitons are generated in the nanocrystals upon light absorption, and electron-hole recombination leads to luminescence. The QDs of disclosure can be synthesized as core / shell structures, where the core nanocrystal is coated with another semiconducting material to protect and enhance its optical properties.Here are some examples of semiconductor materials used in the preparation of DQs (core / shell): CdSe / ZnS, CdTe / ZnS, CdTe / CdSe, CdSe / ZnTe, CdSe / ZnSe, CdTe / ZnSe, InAs / ZnS, InSe / InSe, InA / InA, Cu InP / ZnSe, InAsxPl-x / InP / ZnSe, CdS / ZnSe, CdSe / CdS, ZnSe / CdSe, ZnSe / InP / ZnS, InP / ZnS, InGaP / ZnS, CdSe / CdS / ZnS, or any combination thereof.Exemplary methods for preparing disclosure documents include, but are not limited to: electron beam lithography, focused ion beam technique, etching, chemical precipitation methods, sol-gel methods, microemulsion, hot solution decomposition, vapor deposition, molecular beam epitaxy, physical vapor deposition, chemical vapor deposition, ultrasonic or microwave irradiation, hydrothermal synthesis, solvothermal synthesis, electrochemical assembly, seed-cluster method, or any combination thereof. Chemical precipitation methods may include the nucleation and growth of nanocrystals. Sol-gel methods may involve hydrolysis, condensation, and subsequent gel formation.

[0022] In some cases, the nanoparticle 2 is a polymer nanoparticle. Polymer nanoparticles are colloidal particles having a diameter less than 1 micron (µm). Polymer nanoparticles can form two structures: nanospheres and nanocapsules. Nanospheres are nanoparticles with a solid core or a polymer matrix core. Nanocapsules, on the other hand, are vesicular structures forming an inner reservoir surrounded by an outer membrane, which may contain an oily and / or aqueous core. Polymer nanoparticles can be composed of a synthetic polymer. Non-limiting examples of synthetic polymers used to prepare polymer nanoparticles include polylactide (PLA), polyglycolide (PGA), polylactic-co-glycolic acid (PLGA), polycyanoacrylate, polycaprolactone (PCL), polyethylene glycol (PEG), polystyrene, polyvinyl alcohol (PVA), polyalkylcyanoacrylate, poly(styrene-co-maleic anhydride), etc.Alternatively, disclosure polymer nanoparticles can be composed of natural polymers. Non-limiting examples of natural polymers include cellulose, chitosan, collagen, gelatin, alginate, albumin, hyaluronic acid, and dextran. Non-limiting examples of cellulose types that can be used to prepare the polymer nanoparticle include cellulose acetate, cellulose triacetate, cellulose propionate, cellulose acetate-propionate, cellulose acetate-butyrate, nitrocellulose, cellulose sulfate, methylcellulose, ethylcellulose, ethylmethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, ethylhydroxyethylcellulose, and carboxymethylcellulose. In addition, disclosure polymer nanoparticles can be composed of a combination of synthetic and natural polymers.Polymer nanoparticles can be prepared from a dispersion of preformed polymers. For example, using solvent evaporation, nanoprecipitation, emulsification, salting, dialysis, supercritical fluid technology, or any combination of these techniques. Furthermore, polymer nanoparticles can also be prepared by monomer polymerization, including, for example, emulsion, mini-emulsion, microemulsion, interfacial polymerization, controlled or live radical polymerization, or any combination of these techniques. Other examples of methods for preparing a polymer nanoparticle include coacervation of hydrophilic polymers and desolventization. Polymer nanoparticles can be prepared using one or more of the methods described above, or a combination thereof.Polymer nanoparticles can have a diameter of approximately 50 to 200 nm.

[0023] The sensor 4 comprises a signaling molecule associated with the nanoparticle 2. The sensor 4 can include one or more signaling molecules associated with the nanoparticle 2. In some models, one signaling molecule is associated with the nanoparticle 2. In some examples, two signaling molecules are associated with the nanoparticle 2. In some examples, three signaling molecules are associated with the nanoparticle 2. In some examples, four signaling molecules are associated with the nanoparticle 2. In some examples, five or more signaling molecules are associated with the nanoparticle 2. In the example illustrated in [Fig. 1], the surface of the nanoparticle 2 is decorated with various signaling molecules, including: a pH-sensitive signaling molecule 10, a potassium-sensitive signaling molecule 12, an oxygen-sensitive signaling molecule 14, and a carbon dioxide-sensitive signaling molecule 16.In some cases, the signaling molecule is a non-fluorophore. In some embodiments, the sensor comprises a nanoparticle modified with one or more non-fluorophores such that the fluorescence emission intensity of the nanoparticle (whether or not it contains a signaling molecule) is modified in the presence of one or more analytes. In some examples, the non-fluorophore(s) can modify the fluorescence emission intensity of a signaling molecule associated with the nanoparticle.

[0024] The signaling molecule can exhibit a fluorescence emission intensity that is dependent on the analyte concentration. In some cases, the signaling molecule can decrease or increase the fluorescence intensity of the nanoparticle in the absence of the analyte.In another example, the signaling molecule can decrease or increase the fluorescence intensity of the nanoparticle in the presence of the analyte. Sensor 4 can be a ratiometric sensor. The ratiometric sensor can emit signals continuously (for example, two fluorescence intensities), but the relative ratio of the signals can change depending on the analyte concentration. For example, nanoparticle 2 and the signaling molecule can continuously emit a first and a second fluorescence intensity, respectively, when measured at two or more wavelengths of an emission spectrum or excitation. However, the first or second fluorescence intensity, or both fluorescence intensities, can increase or decrease depending on the analyte concentration.Thus, the ratio of the first fluorescence intensity to the second fluorescence intensity can be measured to detect changes in the concentration of an analyte.

[0025] For example, the signaling molecule can be associated with a quantum dot having a distinct emission wavelength. The signaling molecule can modify the fluorescence emission intensity of the quantum dot as a function of the analyte concentration. In some models, the signaling molecule is a capping molecule. The capping molecule can act as an illuminated fluorescence probe for analyte detection. The capping molecule can decrease the intensity of the quantum dot's fluorescence emission when associated with the quantum dot in the absence of analyte, by acting as a hole trap. The capping molecule, associated with the quantum dot, can form a complex with one or more analytes of interest (e.g., potassium, oxygen, carbon dioxide, and / or hydrogen ions), which further alters the energy position of the most occupied molecular orbital (HOMO) of the capping molecule.Consequently, the capping molecule (associated with the quantum dot and the analyte of interest) transitions to a condition unfavorable for efficient hole transfer; thus, the capping molecule no longer decreases the fluorescence emission intensity of the quantum dot. In this way, the capping molecule acts as a switch that increases the fluorescence emission intensity of the quantum dot in the presence of the analyte of interest. In some models, the capping molecule is p-aminothiophenol.

[0026] In another example, the capping molecule can alternatively decrease the intensity of the fluorescence emission from the quantum dot in the presence of the analyte of interest. In the presence of quenching molecules (i.e., an analyte of interest), a fluorescence signal is reduced due to quenching. For example, when the partial pressure of oxygen (pO2) is increased in a sample, there is an increased number of oxygen molecules that can collide with fluorophores and lead to non-radiative decay (i.e., quenching or a decrease in fluorescence intensity).

[0027] In yet another example, the signaling molecule can be associated with a polymer nanoparticle. One or more signaling molecules can be associated with the polymer nanoparticle. The intensity of the fluorescence emission of the signaling molecules can decrease or increase in response to the presence of the analyte. Conversely, the emission intensity of the signaling molecules can decrease or increase in response to the absence of the analyte.

[0028] The signaling molecule can be incorporated or trapped within a polymer nanoparticle. In yet another example, the signaling molecule can be adsorbed onto an inner and / or outer surface of the nanoparticle 2. In other cases, the signaling molecule can be reversibly or irreversibly coupled to the nanoparticle 2. The signaling molecule can be covalently coupled to the nanoparticle 2. Examples of conjugating chemicals that can be used to couple the signaling molecule to the material of The matrix molecules are known to the skilled craftsman and include, but are not limited to, carbodiimides, N-hydroxysuccinimide esters, imidoesters, maleimids, haloacetyls, pyridyl disulfides, hydrazides, alkoxyamines, aryl azides, diazirines, Staudinger reagent pairs, or any combination thereof. The signaling molecule may include an amine group, and nanoparticle 2 may include a carboxylic acid group, which is amenable to conjugation chemistries (e.g., carbodiimide chemistry). In other examples, the signaling molecule may include a carboxylic acid group, and nanoparticle 2 may include an amine group, which can be conjugated by chemical processes (e.g., carbodiimide chemistry).

[0029] Sensor 4 can be modified with multiple functionalities so that it provides a detectable response for one or more chemical substances (e.g., pH, oxygen, carbon dioxide, and potassium ions). In this example, sensor 4 would be excited by a single wavelength and would emit an independent signal for each detected chemistry. This would eliminate optics such as light-emitting diodes (LEDs) and filters used in conventional detection systems, thereby reducing the cost and complexity of the detection system. Furthermore, another advantage of the disclosure sensors is that a single raw material is manufactured and inspected for all chemistry compared to manufacturing and inspecting multiple raw materials (i.e., one raw material per chemical type).Sensor 4 can detect the concentration of potassium ions, oxygen, carbon dioxide, hydrogen ions, hydronium ions, or any combination of these elements. Additional analytes that Sensor 4 can detect include, but are not limited to, glucose, sodium ions, calcium ions, magnesium ions, chloride ions, creatinine, urea, lactate, bicarbonate, or any combination of these elements. Sensor 4 can detect an analyte concentration in a detection medium such as a biological sample. In some cases, Sensor 4 is embedded in human tissue and comes into contact with a biological sample.

[0030] The term “biological sample,” as used herein, means any suitable biological product that includes an electrolyte, a blood gas, or any other biological analyte. The biological sample may be obtained from a subject. A biological sample may be a fluid (e.g., a biological fluid). In general, a biological fluid may include any fluid associated with living organisms. Non-limiting examples of a biological sample include blood (or blood components, e.g., white blood cells, red blood cells, and / or platelets) obtained from any anatomical location (e.g. tissues, circulatory system, bone marrow) of a subject, interstitial fluid and saliva.

[0031] A biological sample can be obtained from a subject by any means known in the profession. Non-limiting examples of means of obtaining a biological sample directly from a subject include access to the circulatory system (for example, intravenously or intra-arterially by means of a syringe or other needle) and the collection of a secreted biological sample (for example, saliva or urine).

[0032] In some examples, the sensing medium is blood. The blood may be venous and / or arterial. The sensor 4 may be exposed to the sensing medium via a cardiopulmonary bypass circuit in which a pump is used to circulate and oxygenate blood extracorporeally during certain surgical procedures such as, but not limited to, coronary artery bypass grafting and heart valve repair and / or replacement. In some embodiments, the sensing medium is saliva or urine.

[0033] With reference to [Fig. 2], an example of a nanoparticle 2 for the detection of pH, oxygen, carbon dioxide, and potassium ions is schematically represented. In this example, an excitation wavelength 18 is directed at the nanoparticle 2. The excitation wavelength 18 excites a plurality of electrons in the pH-sensitive signaling molecule 10, the potassium-sensitive signaling molecule 12, the oxygen-sensitive signaling molecule 14, and the carbon dioxide-sensitive signaling molecule 16. As a result, the signaling molecules emit light at distinct wavelengths depending on the concentration of one or more analytes of interest. As shown in [Fig. 2], the pH-responsive signaling molecule 10 emits a pH-dependent emission wavelength 20.Signaling molecule 12, sensitive to potassium, emits a potassium-dependent emission wavelength 22. Signaling molecule 14, sensitive to oxygen, emits an oxygen-dependent emission wavelength 24. And signaling molecule 16, sensitive to carbon dioxide, emits a carbon dioxide-dependent emission wavelength 26. The pH-dependent emission wavelength 20, the potassium-dependent emission wavelength 22, the oxygen-dependent emission wavelength 24, and the carbon dioxide-dependent emission wavelength 26 can vary from approximately 300 nanometers (nm) to approximately 900 nm.

[0034] The excitation wavelength 18 can be provided by an energy source. The term "energy source," as used here, generally refers to an energy source that provides a beam of energy. The energy source can provide a beam of electromagnetic energy or electromagnetic radiation. The source Energy can provide a beam of particles. An energy source can provide a beam of light (for example, gamma waves, X-rays, ultraviolet, visible light, infrared light, microwaves, or radio waves). The light beam can be a coherent beam of light, as can be the case with light amplification by stimulated emission of radiation ("laser"). In some examples, the light beam is generated by a laser diode or a multi-diode laser. The excitation wavelength can range from about 300 nanometers (nm) to about 900 nm.

[0035] The signaling molecule may be a fluorophore. Signaling molecules suitable for pH 10 include pH indicators and / or functionalized derivatives of these indicators. The pH-sensitive signaling molecule 10 may be hydroxypyrenetrisulfonic acid ("HPTS"), derivatives thereof, for example salts, and / or mixtures thereof.In some versions, the pH-sensitive signaling molecule 10 is phenolphthalein, fluorescein, phenol red, cresol red, pararosaniline, magenta red, xylenol blue, bromocresol violet, bromophenol blue, bromothymol blue, metacresol violet, thymol blue, bromophenol blue, bromothymol blue, tetrabromophenol blue, bromochlorphenol blue, bromocresol green, chlorophenol red, o-cresolphthalein, thymolphthalein, methanyl diphenylamine yellow, N,N-dimethylaniline, indigo blue, alizarin, alizarin yellow GG, alizarin yellow R, Congo red, methyl red, methyl violet 6B, 2,5-dinitrophenol, and / or various functionalized derivatives of the above species.The components for detecting other ionic species can be made from organic species, including fluorescein, diiodofluorescein, dichlorofluorescein, phenosafrain, rose bengal, bluish eosin I, yellowish eosin, magnesium, tartrazine, eriochrome black T, coumarin, alizarin and others.

[0036] Other components 10 of the pH-responsive signaling molecule that can be used with the sensor 4 include, but are not limited to, the following: 9-amino-6-chloro-2-methoxyacridine; 2',7'-bis-(2-carboxyethyl)-5-(et-6)-carboxyfluorescein; 2',7'-bis-(2-carboxyethyl)-5-(et-6)-carboxyfluorescein, acetoxymethyl ester; 2',7'-bis-(2-carboxyethyl)-5-(et-6)-carboxyfluorescein, acetoxymethyl ester; 5-(et-6)-carboxy-2',7'-dichlorofluorescein; 5-(et-6)-carboxy-2',7'-dichlorofluorescein diacetate; 5-(&-6)-carboxy-4',5'-dimethylfluorescein; 5-(&-6)-carboxy-4',5'-dimethylfluorescein diacetate; 5-carboxyfluorescein; 6-carboxyfluorescein; 5-(&-6)-carboxyfluorescein; 5-carboxyfluorescein diacetate; 6-carboxyfluorescein diacetate; 5-carboxyfluorescein diacetate, acetoxymethyl ester; 5-(&-6)-carboxyfluorescein diacetate; 5-(&-6)-carboxynaphthofluorescein; diacetate of 5-(and -6)-carboxynaphthofluorescein; 5-(and -6)-carboxySNAFL (registered trademark)-1, succinimidyl ester {5'(and 6')-succinimidyl ester-3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one}; 5-(and -6)-carboxySNAFL (registered trademark)-1, succinimidyl ester {5'(and 6')-succinimidyl ester-9-chloro-3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,l'(3'H)-isobenzofuran]-3'-one}; carboxySNAFL (registered trademark)-1 {5'(et6')-carboxy-3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,1'(3'H)-isobenzofuran]-3'-one} ; carboxySNAFL (registered trademark)-1 diacetate {5'(et6')-carboxy-3,10-diacetoxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one} ; carboxySNAFL (registered trademark)-1 {5'(et6')-carboxy-9-chloro-3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one} ; carboxySNAFL (registered trademark)-1 diacetate {5'(and 6')-carboxy-9-chloro-3,10-diacetoxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one};carboxySNARF (registered trademark)-1 {5'(and 6')-carboxy-10-dimethylamino-3-hydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one} ; carboxySNARF (registered trademark)-1, AM acetate (3-acetoxy-5'-acetoxymethoxycarbonyl-10-dimethylamino-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one) ; carboxySNARF (registered trademark)-1 {5'(and 6')-carboxy-10-diethylamino-3-hydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one} ; carboxySNARF (registered trademark)-!, AM acetate {3-acetoxy-5'-acetoxymethoxycarbonyl-10-diethylamine-3-hydroxy-spiro[7H-benzo[c]xanthene-7,l'(3'H)-isobenzofuran]-3'-one} ; carboxySNARF (registered trademark)-6 {5'(and 6')-carboxy-10-diethylamino-3-hydroxy-spiro[7H-benzo[c]xanthene-7,l'(3'H)-isobenzofuran]-3'-one} ; carboxySNARF (registered trademark)-X {5'(and 6')-carboxy-3-hydroxy-tetrahydroquinolizino[l,9-hi]spiro[7H-benzo[c]xanthene-7,l'(3'H)-isobenzofuran]-3'-one} ; 5-chloromethylfluorescein diacetate; 4-chloromethyl-7-hydroxycoumarin;Cl-NERF acid {4-[!-chloro-6-(ethylamino)-7-methyl-3-oxo-3H-xanthene-9-yl]-1,3-benzene-dicarboxylic acid}; dextran, BCECF, 10,000 MW, anionic {dextran, !',7'-bis(!-carboxyethyl)-5(and 6)-carboxy-fluorescein, anionic); dextran, BCECF, 40,000 MW, anionic; dextran, BCECF, 70,000 MW, anionic; dextran, CI-NERF, 10,000 MW, anionic; dextran, Cl-NERF, 70,000 MW, anionic; dextran, Cl-NERF, 10,000 MW, anionic, lysine-fixable; dextran, DM-NERF, 10,000 MW, anionic (dextran, 4-[β,7-dimethyl-6-(ethylamino)-3-oxo-3H-xanthene-9-yl]-1,3-benzene dicarboxylic acid, anionic); dextran, DM-NERF, 70,000 MW, anionic; dextran, DM-NERF, 10,000 MW, anionic, lysine-fixable; dextran, 7-hydroxycoumarin, 10,000 MW, neutral; dextran, 7-hydroxycoumarin, 70,000 MW, neutral; dextran, β-methylumbelliferone; 10,000 MW, neutral; dextran, β-methylumbelliferone, 70,000 MW, neutral; dextran, SNAFL (registered trademark)-1, 10,000 MW, anionic {dextran, 9-chloro-3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]3'-one, anionic}; dextran, SNAFL (registered trademark)-1, 70,000 MW, anionic {dextran, 10-dimethylamino-3-hydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one, anionic}; dextran, SNARF (registered trademark)-1, 10,000 MW, anionic; dextran, SNARF (registered trademark)-1, 70,000 MW, anionic; 1,4-dihydroxyphthalonitrile; DM-NERF {4-[1,7-dimethyl-6-ethylamino)-3-oxo-3H-xanthene-9-yl]l,3-benzene dicarboxylic acid}; fluorescein diacetate; 8-hydroxypyrene-l,3,6-trisulfonic acid, trisodium salt; naphthofluorescein; naphthofluorescein diacetate; SNAFL (registered trademark)-1 {3,10-dihydroxy-spiro[7H-benzo[c]xanthene-7,r(3'H)-isobenzofuran]-3'-one);and SNAFL (registered trademark)-l, diacetate (3,10-diacetoxy-spiro[7H-benzo[c]xanthene-7,l'(3'H)-isobenzofuran]-3'-one}. ;

[0037] The potassium-sensitive signaling molecule 1! may be a coumarocryptand; for example, 6,7-[!.!.!]-cryptando-3-[!"-(5"-carboxy)furyl]coumarin. In some cases, the potassium-sensitive signaling molecule 1! contains a complexing moiety for ion binding and a fluorescent moiety. The compound has a maximum absorbance wavelength of at least approximately 350 nm. Suitable fluorescent moieties may contain excited states close to mr* and ror*. Suitable fluorescent moieties, when coupled to a suitable complexing moiety, may be capable of out-of-plane pleating depending on the ions. Furthermore, the jut* state of the suitable fluorescent moieties may be sufficiently high in energy so that the ion-dependent mixing dominates the non-radiative coupling in the ground state.In some cases, the fluorescent parts include coumarin groups, although other aromatic or nitroaromatic carbonyls or N-heterocyclic groups can be used. Suitable ion-complexing parts include cyclic cage moieties capable of binding an ion. The cage may be able to bind selectively to an ion. In some examples, the ion-complexing parts include cryptand and crown ether groups.

[0038] Ions that can be detected using the ionophore include, for example, Ag+, Ba2+, Ca2+, Ce+, Cd2+, Fr+, Hg2+, K+, Li+, Mg2+, Mn2+, Na+, Pb2+, Ru+, Sr2+, Ti+, and Zn2+. If desired, the ionophore can be used in conjunction with an ion-selective membrane. In some examples, the sensors provided herein include ionophores that detect K+, Na+, and Ca2+.

[0039] In some embodiments, the oxygen-sensitive signaling molecule 14 is benzo[ghi]perylene. The oxygen-sensitive signaling molecule 14 may include fluorescence indicators, including one or more polynuclear aromatic compounds, derivatives of polynuclear aromatic compounds, and others. Examples of such polynuclear aromatic compounds include decacyclene, benzo[ghi]perylene, and coronene. The oxygen indicators may include a mixture of tertiary butyl derivatives of these polynuclear aromatic compounds.

[0040] Other useful oxygen indicators include complexes of ruthenium(II), osmium(II), iridium(III), rhodium, rhenium and chromium(III) with 2,2'-bipyridine, 1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 4,7-disulfonated-diphenyl-1,10-phenanthroline, 2,2'-bi-2-thiazoline, 2,2'-bithiazole, 5-bromo-1,10-phenanthroline, and 5-chloro-1,10-phenthroline, and complexes of Co(II), Cu(II), Pt(II), Pd(II) and Zn(II) with porphyrin, etioporphyrin, tetraphenylporphorin, tetrafluorophenylporphirin, tetrabenzporphirin, tetrafluorobenzporphirin, tetrachlorobenzporphirin, mesoporphirin IX diester, protoporphirin IX dimethyl ester, and octaethylporphorin. Ruthenium complexes are among the metal complexes.

[0041] In some embodiments, the signaling molecule 14 is sensitive to the oxygen concentration in a fluid and comprises one or more polynuclear aromatic compounds and / or one or more derivatives thereof. The polynuclear aromatic compound may be any fluorescent or absorbing optical indicator of the polynuclear aromatic class. The polynuclear aromatic compound from which the indicator component is derived may be selected from the group consisting of perylene, decacyclene, benzoperylene (e.g., benzo[ghi]perylene), coronene, pyrene, porphycin, porphyrin, chlorine, phthalocyanine, and their derivatives and mixtures. Since perylene and its derivatives have relatively low sensitivity to oxygen, other polynuclear aromatic compounds, such as those mentioned herein, may be used when the analyte is oxygen.When an excimer component is to be used, the monomer indicator component may be chosen from a polynuclear aromatic compound, derivatives of that same polynuclear aromatic compound, and mixtures thereof.

[0042] In some cases, the carbon dioxide-sensitive signaling molecule 16 comprises hydroxypyrene 3,6,8-trisulfonic acid, referred to herein as HPTS or hydroxypyrene trisulfonic acid, and its derivatives, for example, HPTS salts. The alkali and alkaline earth metal salts of HPTS can be used by the sensors described herein to detect the carbon dioxide concentration in a fluid. The carbon dioxide-sensitive signaling molecule 16 can be a Absorbance or fluorescence indicators. In detecting carbon dioxide concentrations, examples of absorbance indicators that can be used include chlorophenyl red, cresol bromo violet, nitrophenol, thymol bromo blue, penachloromethane, phenol red, and others. Fluorescence indicators useful for carbon dioxide include the sensors listed above that are useful for pH detection, beta-methylumbelliferone, fluorescein, and others.

[0043] In some embodiments, the sensor 4 is a sensor based on fluorescence resonance energy transfer (FRET). FRET is a mechanism in which energy is transferred between two photosensitive molecules (i.e., chromophores) that are in close proximity to each other, without the emission of a photon. A donor chromophore, initially in an electronically excited state, can transfer energy to an acceptor chromophore by non-radiative dipole-dipole coupling. The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between the donor and acceptor chromophores, making FRET extremely sensitive to small variations in distance. The sensor 4 may comprise a donor chromophore and an acceptor chromophore.The donor chromophore can transfer energy to the acceptor chromophore in the presence of the analyte, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating the presence of the analyte. In some models, the donor and / or acceptor chromophore is a nanoparticle (e.g., a quantum dot or a polymer nanoparticle). In other examples, the donor and / or acceptor chromophore is a fluorescent dye or a protein. In yet another example, both the donor and acceptor chromophores are fluorescent dyes or proteins.Examples of non-limiting fluorescent dyes or proteins used in FRET include cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), green fluorescent protein (GFP), fluorescein, BODIPY FL, tetramethylrhodamine, 5-({2-[(iodoacetyl)amino]ethyl}amino)naphthalene-l-sulfonic acid (IAEDANS), Alexa Fluor 488, Oregon Green, (5-((2-Aminoethyl)amino)naphthalene-l-sulfonic acid) (EDANS), 4-(dimethylaminoazo)benzene-4-carboxylic acid (DABCYL), 4-(4-dimethylaminophenylazo)benzenesulfonyl chloride (DABSYL), QSY(trademark) 7, QSY(trademark) 9, cyanine3 (Cy3), Cy3.5, Cy5.5, Cy7, or any combination thereof. .

[0044] In some examples, the donor chromophore is a quantum dot and the acceptor chromophore is a fluorescent dye. In some cases, the donor chromophore is a nanoparticle and the acceptor chromophore is a fluorescent dye. In some cases, the fluorescent dye is a ratiometric dye. In other cases, the fluorescent dye is a Cy5.5 dye. In some embodiments, the sensor is a nanoparticle having a donor quantum dot core and a fluorescent dye acceptor coating. For example, the nanoparticle may have a quantum dot core and a lipid coating, which includes a fluorescent dye (e.g., Cy5.5). In some cases, the donor chromophore is a fluorescent dye and the acceptor chromophore is a quantum dot or a polymer nanoparticle.

[0045] The sensors described can be modified with "sequestering" molecules that bind the interfering molecules and reduce their impact on accuracy. For example, a sodium-binding cryptand can be immobilized on the surface of a potassium-specific sensor to reduce its potential to interfere with potassium detection. In one such version, the sodium binding may be non-fluorescent and present only to reduce interference. In another example, the nanomaterial may bind sodium and provide a concentration-dependent response, so that the interference on potassium accuracy is reduced and the sensor reports the sodium concentration.

[0046] In some embodiments, the sensor is sensitive to temperature. In some embodiments, the sensor may include a temperature-sensitive channel, so that the sensor's output signal (for example, a fluorescence emission intensity or a ratio of two fluorescence emission intensities) responds to a change in temperature. In some examples, such a temperature-dependent signal can be used as a reference for temperature correction. In some embodiments, the sensor comprises a nanoparticle or signaling molecule exhibiting a fluorescence emission intensity that is a function of temperature (for example, the temperature of a sample).In some embodiments, the sensor includes a donor chromophore transferring energy to an acceptor chromophore as a function of temperature, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating a temperature change (e.g., a temperature change in a sample). For example, the sensor may include a quantum dot that exhibits temperature-sensitive photoluminescence.

[0047] According to one aspect, the present description provides a method for detecting the concentration of an analyte in a fluid. The method may consist of providing one or more sensors comprising a matrix material, a nanoparticle associated with the matrix material, and a signaling molecule associated with the nanoparticle. The signaling molecule or the nanoparticle exhibits a fluorescence emission intensity that depends on the analyte concentration. Then, the method may... This involves exposing one or more sensors to the fluid. For example, the sensor(s) could be part of a cardiopulmonary bypass circuit, placed along a tube in fluidic connection with a patient's blood. In another example, the sensor(s) could be connected to a continuous-flow cell that has fittings on opposite sides for coupling to the circuit's tubing.

[0048] Next, the method may consist of measuring the intensity of the fluorescence emission. The sensor may be optically coupled to a measuring device that provides a measurement of the intensity of the fluorescence emission. The sensor may be remotely coupled to the measuring device. In other words, the measuring device may be a remote measuring device. The measuring device may be a blood gas analyzer. The measuring device may include: a power source to direct light to one or more sensors, a device to analyze the light reflected by one or more sensors, and a monitor to provide a visual display of the measurement.In some cases, the measurement device may include a bundle of optical fibers running from the remote device to a transmission block or retaining device and a removable connector allowing the block or retaining device to be removably connected to a cell or housing that supports the sensors.

[0049] Next, the method may include detecting the analyte based on the measured fluorescence intensity. Once light from an energy source is directed at one or more sensors, the light emitted by that sensor or those sensors is detected. The light emitted by one or more sensors can be detected by a detector (for example, a photodiode). The detector can then send the light signal to a converter, which converts the emitted light into a digital signal. In another example, the detector can send the light signal to an amplifier, which amplifies the light signal before transmitting it to the converter. After the emitted light has been converted into a digital signal, the controller can send the digital signal to a controller and / or the monitor. The controller can be operationally connected to the monitor and the energy source. The controller can receive instructions from the monitor.The transmitted digital signal can be one or more measured values ​​of fluorescence intensity.

[0050] Although a number of examples have been described by way of illustration, the foregoing description is not intended to limit the scope of the invention, which is defined by the scope of the appended claims. There are and will be further examples and variations within the scope of the following claims.

Claims

Demands

1. Sensor (4) for detecting the concentration of one or more analytes, the sensor comprising: - a matrix material; - a nanoparticle (2) associated with the matrix material; and - a signaling molecule (10, 12, 14, 16) associated with the nanoparticle, wherein the nanoparticle or the signaling molecule exhibits a fluorescence emission intensity (20, 22, 24, 26) as a function of the concentration of one or more analytes, wherein the analyte(s) include potassium and / or oxygen, and wherein the signaling molecule includes benzo[ghi]perylene and / or a coumarocryptand.

2. Sensor according to claim 1, wherein the analyte further comprises carbon dioxide and / or a hydrogen ion.

3. Sensor according to claim 1, wherein the matrix material is an analyte-permeable hydrogel matrix.

4. Sensor according to claim 1, wherein the nanoparticle is a polymer nanoparticle.

5. Sensor according to claim 1, wherein the nanoparticle is a quantum dot.

6. Sensor according to claim 5, wherein the quantum dot has an emission wavelength that can be distinguished.

7. Sensor according to claim 5, wherein the signaling molecule modifies a quantum dot fluorescence emission intensity as a function of the analyte concentration.

8. Sensor according to claim 1, wherein the signaling molecule decreases or increases the fluorescence emission intensity of the nanoparticle in the absence of the analyte.

9. Sensor according to claim 1, wherein the signaling molecule increases or decreases the fluorescence emission intensity of the nanoparticle in the presence of the analyte.

10. Sensor according to claim 1, wherein the signaling molecule is a fluorophore.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24. Sensor according to claim 1, wherein the signaling molecule is a non-fluorophore molecule. A sensor according to claim 1, wherein the signaling molecule further comprises hydroxypyrenetrisulfonic acid. A sensor according to claim 1, wherein the sensor is optically coupled to a measuring device. Sensor according to claim 1, wherein the sensor is a ratiometric sensor. Sensor according to claim 1, wherein the nanoparticle or signaling molecule exhibits a fluorescence emission intensity as a function of temperature. Sensor for detecting the concentration of one or more analytes, the sensor comprising: - a matrix material; - a donor chromophore; and - an acceptor chromophore, where the donor chromophore transfers energy to the acceptor chromophore in the presence of the analyte, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating the presence of the analyte, where the analyte(s) include potassium and / or oxygen. Sensor according to claim 16, wherein the analyte further comprises carbon dioxide and / or a hydrogen ion. Sensor according to claim 16, wherein the matrix material is an analyte-permeable hydrogel matrix. Sensor according to claim 16, wherein the donor chromophore or the acceptor chromophore is a nanoparticle. Sensor according to claim 19, wherein the nanoparticle is a polymer nanoparticle. Sensor according to claim 19, wherein the nanoparticle is a quantum dot. A sensor according to claim 16, wherein the acceptor chromophore or the donor chromophore is a fluorescent dye. A sensor according to claim 16, wherein the sensor is optically coupled to a measuring device. Sensor according to claim 16, wherein the sensor is a ratiometric sensor.

25. Sensor according to claim 16, wherein the donor chromophore transfers energy to the acceptor chromophore as a function of temperature, causing the acceptor chromophore to exhibit a distinct emission wavelength indicating a temperature change.

26. Method for detecting the concentration of one or more analytes in a fluid, the method comprising: - providing one or more sensors comprising: - a matrix material - a nanoparticle associated with the matrix material; and - a signaling molecule associated with the nanoparticle, wherein the signaling molecule or the nanoparticle exhibits a fluorescence emission intensity that depends on the concentration of one or more analytes; - exposing the sensor(s) to the fluid; - measuring the intensity of the fluorescence emission; and - detecting the analyte based on the measured fluorescence intensity, wherein the analyte(s) comprise potassium and / or oxygen, and wherein the signaling molecule comprises benzo[ghi]perylene and / or a coumarocryptand.

27. ​​Method according to claim 26, wherein the fluid is a biological fluid.

28. Method according to claim 27, wherein the biological fluid is blood.

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