CN117413170A

CN117413170A - Optical system for analyte detection

Info

Publication number: CN117413170A
Application number: CN202180096827.5A
Authority: CN
Inventors: 希尔帕·本德; 考沙尔·沙希坎特·萨加尔; 丽萍·莎朗·谢; 莫迪凯·科恩布鲁斯
Original assignee: Shuizhi Co ltd
Current assignee: Shuizhi Co ltd
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2024-01-16
Also published as: WO2022173432A1

Abstract

The optical system includes: a fluorescent-based chemical sensor configured to emit fluorescence upon reaction of the chemical sensing molecule with the analyte; a modulated light source configured to generate a light beam having a wavelength responsive to an excitation wavelength of the chemical sensor, the light being transmitted through free space; a collimating lens configured to collimate and diffuse the modulated light; a dichroic mirror arranged to reflect the modulated light onto the chemical sensor and to transmit the light re-emitted from the chemical sensor onto the photodetector; and a lens upstream of the photodetector configured to focus the re-emitted light onto the photodetector.

Description

Optical system for analyte detection

Technical Field

The present disclosure relates to fluorescence-based chemical sensors, particularly real-time analyte chemical sensors in aqueous media, such as solid ammonia chemical sensors, and methods of use thereof.

Background

Identification and monitoring of various ions such as heavy metals and minerals in water and other liquid media has been used in a variety of industries, including agriculture, water management, and medical analysis. Various fluorescent-based chemical sensors have been developed, but their use presents obstacles, particularly with respect to the complex media whose composition complicates analyte detection. Another obstacle is the development of devices that can detect fluorescence generated by chemical sensors in a meaningful and practical way.

SUMMARY

In one or more embodiments, an optical system is disclosed. The optical system includes a fluorescence-based chemical sensor configured to emit fluorescence when the chemical sensing molecule reacts with the aquaculture analyte and when excited by light; a modulated light source configured to generate a light beam having a wavelength responsive to an excitation wavelength of the chemical sensor, the light being transmitted through free space; a collimating lens configured to collimate and diffuse the modulated light; a dichroic mirror arranged to reflect the modulated light onto the chemical sensor and to transmit the light re-emitted from the chemical sensor onto the photodetector; and a lens upstream of the photodetector configured to focus the re-emitted light onto the photodetector, the optical system being enclosed in a waterproof, corrosion resistant enclosure. The aquaculture analyte may be ammonia. The optical system may be a real-time analysis sensor. The lens may be an asymmetric lens configured to focus the re-emitted light before it enters the photodetector. The optical system may further comprise one or more color filters. The optical system may be housed in a portable aquaculture aqueous sensing device.

In another embodiment, a real-time ammonia sensing device for an aquaculture aqueous medium is disclosed. The sensing device includes an optical system having a light source configured to generate a light beam having a first wavelength to be transmitted through free space; a collimator configured to collimate light, and a dichroic mirror configured to reflect the collimated light of the first wavelength onto a fluorophore-containing chemical sensor configured to react with an analyte in an aquaculture aqueous medium sample and to transmit light of a second wavelength re-emitted from the chemical sensor onto a photodetector. The sensing device also includes an electronic system having a microprocessor programmed to receive a signal corresponding to the light re-emitted from the photodetector and provide information in real time based on the signal. The first wavelength is an excitation wavelength of the chemical sensor. The second wavelength is different from the first wavelength. The optical and electronic systems may be sealed from contact with the aquaculture aqueous medium. The device may be portable. The device may include a waterproof, corrosion-resistant housing. The chemical sensor may be housed in a compartment accessible to the aquaculture aqueous medium.

In yet another embodiment, an aquaculture medium ammonia sensing device is disclosed. The apparatus includes a housing including a modulated light source configured to generate a light beam having a first wavelength that is dependent on an excitation wavelength of a fluorescence-based chemical sensor, the light being transmitted through free space; a collimating lens configured to collimate and diffuse the modulated light; a dichroic mirror configured to reflect the modulated light onto the chemical sensor and transmit the light re-emitted from the chemical sensor onto the photodetector; and a lens upstream of the photodetector configured to focus the re-emitted light onto the photodetector. The ammonia sensor further includes a compartment attached to the housing and including a fluorescent-based chemical sensor configured to re-emit light when the chemical sensing molecules react with ammonia in the aquaculture aqueous medium sample. The housing may be waterproof and corrosion resistant. The compartment may be configured to enable the chemical sensor to be in contact with the aquaculture aqueous medium. The housing may also include an electronic system including a microprocessor programmed to receive signals from the photodetector. The microprocessor is programmed to communicate with another electronic device. The device may be a portable device. The device may be a real-time aquaculture ammonia sensor.

Brief Description of Drawings

FIG. 1 is a schematic diagram of a photo-induced electron transfer (PET) mechanism used in a chemical sensor;

FIG. 2 is a combination plot generally used to predict unknown concentrations of ions/analytes in an aqueous environment by measuring fluorescence from a chemical sensor;

FIG. 3A is a schematic illustration of a chemical sensor structure disclosed herein, including a matrix network with embedded particulates and a surfactant system;

FIG. 3B shows a detailed view of a portion of the chemical sensor of FIG. 3A;

FIG. 3C shows a detailed view of the microparticle with surfactant system of FIG. 3B;

FIG. 3D shows a non-limiting example of a chemical sensing molecule of a chemical sensor disclosed herein;

FIG. 4 shows a non-limiting example of a chemical sensor disclosed herein incorporated into a chemical sensing structure comprising multiple layers;

FIG. 5 presents a graph showing the results of a real-time titration experiment using seawater as an aqueous medium, ammonia as an analyte, and using the chemical sensor disclosed herein to identify the analyte in the medium;

FIG. 6 shows one non-limiting example of an optical analysis system using the chemical sensor disclosed herein;

FIG. 7 shows another non-limiting example of an optical system with a chemical sensor as disclosed herein;

FIG. 8 shows an apparatus using an optical and electrical system with a chemical sensor as disclosed herein; and

fig. 9 shows an exploded view of a compartment housing a chemical sensor within the device shown in fig. 8.

Detailed description of the preferred embodiments

Embodiments of the present disclosure are described herein. However, it is to be understood that the disclosed embodiments are merely examples and that other embodiments may take on various alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present embodiments. As will be appreciated by those of ordinary skill in the art, various features illustrated and described with reference to any one drawing may be combined with features illustrated in one or more other drawings to yield embodiments that are not explicitly illustrated or described. The combination of the illustrated features provides representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

Except in the examples, or where otherwise indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word "about" in describing the broadest scope of the disclosure. It is generally preferred to implement within the specified numerical limits. Furthermore, unless expressly indicated to the contrary, percentages, "parts" and ratio values are by weight; a group or class of materials being described as suitable or preferred for a given use in connection with the present disclosure means that a mixture of any two or more members of the group or class is equally suitable or preferred; describing the components in chemical terms refers to the components when added to any combination specified in the specification, and does not necessarily preclude chemical interactions among the components of the mixture once mixed.

The first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies to normal grammatical variations of the initially defined abbreviation. Unless explicitly indicated to the contrary, measurement of a property is determined by the same technique as previously or later mentioned for the same property.

It must also be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.

The terms "substantially," "generally," or "about" as used herein mean that the amount or value referred to may be the particular value specified or another value in the vicinity thereof. Generally, the term "about" indicating a particular numerical value is intended to indicate a range within ±5% of that numerical value. As an example, the phrase "about 100" refers to a range of 100±5, i.e., a range of 95 to 105. In general, when the term "about" is used, it is contemplated that similar results or effects according to the present disclosure may be obtained within ±5% of the indicated values. The term "substantially" may modify a numerical value or relative characteristic disclosed or claimed in the present disclosure. In such cases, "substantial" may mean that the numerical value or relative characteristic to which it is modified is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the numerical value or relative characteristic.

It should also be appreciated that the integer range explicitly includes all integers in between. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, ranges 1 to 100 include 1, 2, 3, 4..97, 98, 99, 100. Similarly, when any range is recited, intermediate values divided by 10 increments by the difference between the upper and lower limits can be substituted for the upper or lower limits. For example, if the range is 1.1 to 2.1, the following values 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 may be selected as the lower limit or the upper limit.

In the examples given herein, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rates, etc.) may be applied to +or-50% of the indicated values, rounded or truncated to the two significant digits of the values provided in the examples. In one refinement, the concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow, etc.) may be applied to +or-30% of the indicated values, rounded or truncated to the two significant digits of the values provided in this example. In another refinement, the concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow, etc.) may be applied to +or-10% of the indicated values, rounded or truncated to the two significant digits of the values provided in this example.

For representation as having multiple letters and numbersEmpirical formulas for subscripts (e.g., CH ₂ O) the subscript may be +or-50% of the indicated value, rounded or truncated to the two significant digits. For example, if CH is indicated ₂ O is of formula C _(0.8-1.2) H _(1.6-2.4) O _(0.8-1.2) Is a compound of (a). In one refinement, the value of the subscript may be +or-30% of the value shown, rounded to or truncated to a two-digit significant number. In another refinement, the value of the subscript may be +or-20% of the value shown, rounded to or truncated to a two-digit significant number.

The term "and/or" as used herein means that all or only one element of the set may be present. For example, "a and/or B" means "a alone, or B alone, or a and B". In the case of "a only", the term also covers the possibility that B is not present, i.e. "a only, but no B".

It is also to be understood that this disclosure is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is for the purpose of describing particular embodiments of the disclosure only and is not intended to be limiting in any way.

The term "comprising" is synonymous with "including", "having", "containing" or "characterized by". These terms are inclusive and open-ended and do not exclude additional unrecited elements or method steps. The terms "comprising" or "including" can encompass the phrases "comprising," consisting of …, "and/or" consisting essentially of ….

The phrase "consisting of …" excludes any element, step or component not specified in the claims. When such a phrase appears in the clause of the subject matter of the claims, not immediately after the preamble, it only limits the elements recited in that clause; no other element is excluded from the whole claim.

The phrase "consisting essentially of …" limits the scope of the claims to those materials or steps that specify the materials or steps and those material(s) that do not materially affect the basic and novel characteristics of the claimed subject matter.

With respect to the terms "comprising," "consisting of …," and "consisting essentially of …," when one of these three terms is used herein, the subject disclosure and claimed subject matter may include the use of either of the other two terms.

The term "one or more" means "at least one," and the term "at least one" means "one or more. The terms "one or more" and "at least one" include "a plurality" as a subset.

A group or class of materials being described as suitable for a given use in connection with one or more embodiments means that a mixture of any two or more members of the group or class is suitable. Describing the components in chemical terms refers to the components when added to any combination specified in the specification, and does not necessarily preclude chemical interactions among the components of the mixture once mixed. The first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies to normal grammatical variations of the initially defined abbreviation. Unless explicitly indicated to the contrary, measurement of a property is determined by the same technique as previously or later mentioned for the same property.

Ensuring the quality of water has become a focus of worldwide attention. Efforts have been made to remove contaminants in drinking water as well as wastewater, reclaimed water and water for aquaculture. Some of these contaminants are heavy metal ions, such as lead ions (Pb ²⁺ ) Arsenic ions (As) ³⁺ Or As ⁵⁺ ) Mercury ions (Hg) ²⁺ ) Chromium ion (Cr) ²⁺ Or Cr ⁶⁺ ) Or cadmium ion (Cd) ²⁺ ) They can have deleterious health effects on humans, animals and/or aquatic organisms. Important analytes include dissolved ammonia (NH) in water ₃ ) Or gaseous NH ₃ 。

Ammonia is a nutritive inorganic nitrogen compound that naturally occurs in air, soil, water, and living tissue. Ammonia may require periodic monitoring. This is in combination with NH ₃ Toxicity in water is related to the adverse effects of living organisms. The increased ammonia content in the wastewater and regenerant water is also important because it directly affects the efficiency gains of the water treatment process. In seawater for aquaculture, ammonia is directly usedWhich in turn affects the health and yield of agricultural organisms. Improper NH ₃ The level can affect the entire aquaculture pond, potentially damaging the entire crop. Over-fertilization to increase NH in fresh water resources, such as in agriculture ₃ Horizontal to cause groundwater contamination. Monitoring NH in drinking water for health reasons ₃ The level is also important. Thus NH ₃ Is important in any type of water in various environments.

But NH in any aqueous medium ₃ Detection is technically challenging. This is due to NH ₃ And NH ₄ ⁺ Forms are all present in water. NH (NH) ₃ And NH ₄ ⁺ The chemical equilibrium of the concentration is mainly dependent on different factors, including the possible presence of NH therein ₃ And NH ₄ ⁺ Temperature, pH and salinity of the aqueous medium of (c). The ionized form of ammonia is harmless, but it is difficult to detect NH in water using conventional methods ₄ ⁺ With NH ₃ And (5) separating.

Ion sensing techniques have been used to detect ions in fluid media (e.g., water). For example, fluorescent-based detection methods have been used to sense ions in water, including heavy metal ions, where the ions are bound to a detection molecule (e.g., a chemical sensor) to generate or quench fluorescence. Measuring fluorescence can then determine the ion concentration in the water.

However, conventional fluorescent-based detection methods may exhibit different sensitivities to different ions due to the different sizes and charges of the different ions and the different binding energies required to bind to the different detection molecules. Therefore, in order to accurately detect the presence of target ions in a fluid medium, detection molecules need to be selectively bound to the target ions with high sensitivity. And NH is carried out in the detection process ₄ ⁺ With NH ₃ The separation-related difficulties thus lead to difficulties in the sensing process, because of the NH ₄ ⁺ May replace the desired NH ₃ To the detection molecule or vice versa.

To measure NH using chemical sensing method ₃ Most prior art cokesThe point is that hydrophilic ions, such as Ca, are filtered out using a "chemical filter" or microporous hydrophobic membrane process ²⁺ 、Mg ²⁺ 、Na ⁺ And NH ₄ ⁺ . Dissolved NH ₃ And then interact with pH sensing molecules immobilized in a hydrophobic matrix to generate an optical signal that is calorimetric or fluorescent in nature. But with NH in aqueous medium ₃ Another technical challenge related thereto is its measurement range. Typically, NH in water ₃ Trace level detection is required so that a pH sensor based approach is difficult because of the presence of NH from trace levels ₃ The pH change of the interaction may be insufficient to meet the NH in water ₃ The required sensing resolution. In addition, dissolved CO ₂ Or any other trace organic molecules may also interfere with the pH sensing molecules due to their selective filtration into the hydrophobic matrix layer to affect NH using the pH sensor method ₃ And (5) detecting.

In general, receptor-spacer-fluorophore type sensors can be used to identify ions/analytes. Such sensors may utilize light induced electron transfer (PET). An exemplary chemical sensor and PET principle is shown in fig. 1. Chemical sensor 10 may include a fluorophore 12. Fluorophore 12 is covalently linked to ion/analyte receptor 14 through non-conjugated spacer group 16. Unbound receptors 14 have a higher energy than the excited fluorophores 12 in the absence of ions/analytes 18. This energy difference, as well as other factors, drives the rapid transfer of electrons from acceptor 14 to excited state fluorophore 12, thereby quenching the fluorescence. When the acceptor 14 binds to the ion/analyte 18, the energy level of the acceptor electron pair is lower than the energy level of the excited fluorophore 12; electrons are not energetically favored and therefore fluorescence is "on".

The change in fluorescence intensity relative to ion/analyte concentration can be used to form a main curve, an example of which is shown in fig. 2, which can be used to predict an unknown concentration of ion/analyte in an aqueous environment by measuring fluorescence from a sensor. Such chemical sensors have been used to realize low cost, high sensitivity (ion concentration in the ppm range), on-line, real-time sensors for water quality monitoring.

It is important to note that the above PET effect can only be promoted in hydrophilic environments. Thus, to facilitate this sensing mechanism, atypical chemical sensor designs use hydrophilic crosslinked polymer matrices or hydrogels to house the chemical sensing molecules. This not only promotes the PET effect necessary for sensing, but also ensures a smooth exchange of ions/analytes from the water onto the sensor.

But when used in complex media such as wastewater or seawater, such a system is useful in detecting non-polar targets such as NH ₃ Problems are often encountered. For example, seawater is a complex medium with extremely high concentrations of interfering ions, such as calcium (Ca), magnesium (Mg), potassium (K), and/or sodium (Na) ions. The concentration may be about 100-10000ppm, depending on the source of the water. Any specific chemosensing reaction is unlikely to occur in the presence of such high concentrations of interfering ions. Such systems may also be susceptible to sensor hysteresis, where sensor performance is unreliable.

Thus, there is a need to be able to detect complex media, such as seawater, wastewater, and other types of aqueous media, including body fluids, such as NH in blood ₃ Is provided.

In one or more embodiments, chemical sensors are disclosed that overcome one or more of the above-listed disadvantages. The chemical sensor is a sensor of chemical means. The chemical sensor is arranged, designed and/or configured to detect ammonia NH in an aqueous environment comprising a complex aqueous medium ₃ . The aqueous environment/complex aqueous medium may be fresh water, brackish water, sea water, recycled water, reservoir water, water treatment facilities or other processing facilities such as waste water, body fluids, animal fluids, blood, etc. in meat processing plants.

One non-limiting example of a chemical sensor is schematically depicted in fig. 3A. The chemical sensor 100 may include a hydrophobic portion and a hydrophilic portion. The chemical sensor may include a hydrophobic matrix or network 102. The matrix 102 may be a cross-linked matrix. The matrix 102 is a selective matrix. The substrate 102 is configured to permit NH only ₃ Species enter, entrap, enrich and/or capture while rejecting other hydrophilic species. The matrix 102 is configured to entrap analytes, sensing molecules or molecules to be detected, such as NH ₃ . At the same time, the matrix or network 102 is also configured to prevent the influx or ingress of other compounds, such as any other compounds other than the analyte of interest. For example, the matrix or network 102 is configured or structured to prevent any non-ammonia species or compounds from entering the network 102. The matrix or network 102 may be configured to prevent inflow of the sample matrix, i.e., any other compounds in the aqueous sample other than the analyte. The matrix or network 102 may be configured to prevent the influx or ingress of interfering ions, such as Ca, K, na, or Mg. The matrix 102 further inhibits NH ₄ Enter to NH ₄ Deprotonation. When NH ₄ Upon deprotonation, the substrate 102 is configured to accept NH ₃ 。

The matrix or network 102 comprises a hydrophobic material. The matrix 102 may include crosslinked hydrophobic polymer(s). Non-limiting exemplary hydrophobic materials can include silicone-based polymers such as polydimethoxysiloxane, silicone, polybutadiene, polyisoprene, and the like, or combinations thereof. The matrix 102 may be a silicone crosslinked matrix.

The matrix 102 may form or include a cross-linked network 103. The network 103 may include interconnects that form gaps 105 between the crosslinked materials. The network 103 may be formed as a single layer or as multiple layers. The gaps 105 between the various branches of the network may be of the same or different sizes. The gap 105 may contain other components of the chemical sensor 100, such as the microparticles 104, the chemical sensor molecules 106, the surfactant system 108, the buffer system 114, the co-solvent 118, or a combination thereof.

The chemical sensor 100 includes a microparticle 104 having chemical sensing molecules 106, schematically depicted in fig. 3A-3C. The particulates 104 may be disposed within the matrix 102, in the gaps 105, or both. The particles 104 have a smaller diameter than the gaps 105. The particles 104 may have the same or different sizes and/or shapes. The particles 104 may have regular, irregular, spherical, or other shapes. The particles 104 may comprise the same or different materials. The particles 104 may include a mixture of different particles. The microparticles 104 may comprise a material such as a polymer, silica, cellulose, metal organic framework, or a combination thereof.

The chemical sensing molecule 106 may include a fluorophoreBinding sites, fluorophores, spacer groups, receptors, side chains, or combinations thereof. The chemical sensing molecules 106/fluorophores may include two or more combined aromatic groups or planar or cyclic molecules with several pi bonds. The chemical sensing molecule 106 may include and/or the fluorophore may be anthracene, benzene, carbazole, diphenylfuran, naphthalene, 1,8 naphthalene dicarboximide, porphyrin, and/or pyrene. Fluorophores are fluorescent compounds configured to re-emit light upon excitation by light. The spacer groups may include secondary amines, hydrocarbon chains, and/or one or more organic rings adjacent to the fluorophore. The side chain may be optional. The side chain may include one or more ether groups. The receptor may include one or more analyte binding sites, one or more ether groups, and/or amine groups. The receptor may form a coronal structure. The chemosensing molecules may utilize the PET principle described above. With NH ₄ ⁺ A schematic of the chemical sensing molecule upon interaction is shown in fig. 3D.

The chemical sensing molecules 106 may be coated onto the surface of the particles 104. The chemical sensing molecules 106 may be applied and/or covalently linked or bonded to the microparticles 104. The chemical sensing molecules 106 may be attached to at least a portion, or the entire surface of at least some or all of the particles 104. The chemical sensing molecules 106 may be mixed with the material from which the particles 104 are made such that the chemical sensing molecules 106 are on the surface and/or within the particles 104.

The chemical sensor 100 further includes a surfactant system 108. The surfactant system 108 may include one or more nonionic surfactants. Surfactants, including nonionic surfactants, include hydrophilic head groups 110 and hydrophobic tails 112. Nonionic surfactants are neutral and are uncharged at their tail. When a sufficient amount of surfactant molecules are present in the solution, the molecules combine together to form a structure known as a micelle. When micelles form in a hydrophobic macroscopic environment, the surfactant head groups position themselves to expose them to water, while the tail groups aggregate together at the structural center that is kept away from the water.

The chemical sensor 100 includes a reverse micelle or reverse micelle as part of the nonionic surfactant system 108. Reverse micelles are thermodynamically stable assemblies of surfactant molecules surrounding water or hydrophilic nuclear tissue that solubilize solutes, which spontaneously form optically clear solutions in low polarity liquids. Reverse micelles are micelles in which the effects of the nonpolar and polar phases are reversed and the orientation of the surfactant molecules is reversed such that the head group 110 is directed to a closed volume containing the polar phase. The nonionic surfactant system 108 is configured to have a stable reverse micelle structure due to its chemical synergy with the matrix or network 102.

Non-limiting examples of surfactants may include Triton ^TM (nonionic surfactant having a hydrophilic polyethylene oxide chain and an aromatic lipophilic or hydrophobic group), polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), silicone-based surfactants, and the like, or combinations thereof.

The chemical sensor 100 may optionally include a buffer or buffer system 114. Micelles of nonionic surfactant have hydrophilic cores 116. The core 116 may include a buffer. All or only a portion of the cores may include a buffer. Buffers may include a compound, a system of compounds, or a mixture of compounds.

The buffer may have a relatively low concentration of about a few nM, such as 0.5 to 2nM or 1 nM. Buffers provide a favorable environment for chemical sensing. By using NH configured to assist in entry ₃ Protonation to NH ₄ ⁺ And back to NH when needed ₃ Is configured for high pH of about 8 to 9 and low buffer capacity conditions of about 1 to 10 nM.

Buffers may be provided to maintain the pH of the hydrophilic system near NH ₃ To facilitate NH ₃ Conversion to NH ₄ ⁺ . Since the pH is close to the pKa value of ammonia, the buffer helps to maintain NH inside the micelle ₄ ⁺ And NH outside in hydrophobic matrix phase ₃ Chemical dynamic balance between the two.

Non-limiting examples of buffers can include Tris buffer (Tris (hydroxymethyl) aminomethane), HEPES (2- [4- (2-hydroxyethyl) piperazin-1-yl ] ethanesulfonic acid), PBS (phosphate buffered saline), and the like, or combinations thereof.

Chemical sensor 100 can be anyOptional inclusion of NH configured to adjust at lower or higher concentration ranges ₄ ⁺ Dissociation constant K of binding _d Is a compound of (a). The compound may be a solvent, also referred to herein as a co-solvent. The term co-solvent is used because the medium or sample to be tested includes water as the solvent. The term co-solvent thus distinguishes between water contained in the test medium/sample and compounds configured to modulate the dissociation constant. Since the test medium is an aqueous medium, the aqueous medium may surround the chemical sensor when the chemical sensor is immersed or otherwise in contact with the medium. The medium may be mixed with one or more liquid portions of the chemical sensor.

The co-solvent 118 may be present in the core(s) of the reverse micelles of the nonionic surfactant. The co-solvent may be configured to regulate NH at a lower or higher concentration range ₄ ⁺ Dissociation constant of the binding. The cosolvents thus chemically adjust the dissociation constant K _d Which controls the analyte (NH ₃ ) Binding energy to the binding site of the chemical sensor. The co-solvent thus chemically modulates the overall sensitivity range of analyte detection.

Dissociation constant K _d The binding energy is related by the following relationship:

K _d ＝c ₀ e ^ΔG/kT ,

wherein c ₀ Is the standard reference concentration (1 molar),

ΔG is the sum of the binding free energy (usually negative number)

kT is the temperature in energy units.

Thus, tighter binding reduces Δg (more negative) and reduces dissociation constant, resulting in higher sensitivity. The free energy of binding is equal to the free energy of the bound state minus the free energy of the unbound (solvated) state. Due to ionic charge, solvation energy is largely dependent on the dielectric properties of the solvent, i.e. electrostatic interactions between the solvent and the charged ions. This varies with the co-solvent so that the co-solvent(s) can act as a tuning knob for binding energy and thus sensitivity.

One non-limiting example of a co-solvent may include glycerol, ethylene glycol, sucrose, polyacrylic acid, polyvinyl alcohol, and the like, or a combination thereof.

The chemical sensor may comprise a mixture of a buffer system and a co-solvent(s). In another embodiment, the chemical sensor may be free of a buffer system, but include a co-solvent(s). In another embodiment, the chemical sensor may be free of co-solvent(s), but include a buffer system. In yet another embodiment, the chemical sensor may be free of buffer system and co-solvent(s).

Typically, chemical sensor molecules are designed and synthesized to conform to the analyte measurement range. This approach is impractical because the electronic potential of the different chemicals used in sensor fabrication will affect the overall performance of the sensor in a given set of conditions. To overcome this disadvantage, the chemical sensors disclosed herein may include both a buffer and a co-solvent(s). The buffer and the co-solvent(s) may form a mixture.

The resulting chemical sensor is configured to facilitate: 1) Hydrophilic environment required for PET effect and thus promote chemical sensing, 2) NH ₃ And NH ₄ ⁺ Dynamic equilibrium conditions between, and/or 3) adjust NH as desired ₃ Measuring range of detection without changing NH ₄ ⁺ Basic chemical structure of specific chemical sensor molecules.

In the chemical sensors disclosed herein, the reverse micelles may encapsulate the microparticles 104. All, some, or at least one of the particles 104 may be encapsulated or captured by the reverse micelles of the surfactant system 108. The surfactant reverse micelle head may be directed toward the core 116 surrounding the particle 104. The matrix 102 can form a base of the particulates 104, and the surfactant system 108 can encapsulate, surround, or enclose individual particulates 104 within the matrix 102. Thus, when NH is derived from the test medium ₃ When encountering the chemical sensor structure, it enters reverse micelle and is protonated into NH ₄ And reacts with chemical sensing molecules 106 present on the particles 104. Fluorescence of the chemical sensing molecule 106 upon photoexcitation caused by interaction of the chemical sensing molecule 106 with the analyteThe light is now indicative of NH in the test medium ₃ Is present.

When the chemical sensor 102 interacts with a test medium, herein referred to as seawater, wastewater, blood, etc., the chemical sensor 102 may include water as a solvent present in the test medium.

The chemical sensor 102 may be incorporated into a more complex structure. One non-limiting example of a structure 150 is shown in fig. 4. As can be seen in fig. 3, the chemical sensor 102 may be part of a multi-layer structure or film 150. The chemical sensor 102 may form a top layer 120 that is adhered to a transparent substrate 122. Adhesion may be provided via the adhesive layer 124. The chemical sensor 102 may include a layer having a black tint, such as carbon black, to prevent random, unexpected sensor-light interactions from ambient light from occurring.

By adjusting NH in the hydrophobic matrix phase inside and outside the micelle ₃ Concentration, ammonium can be removed from the reverse micelle environment by chemical dynamic equilibrium to reset the chemical sensor 100. NH can also be driven by applying a pH increase ₄ ⁺ →NH ₃ +H ⁺ Reacts to achieve the desired reset. The pH increase may be applied by an electrochemical component, such as by applying a voltage, injecting a buffer solution, or adding other solutes.

The chemical sensor described herein can be prepared by the following method. Microparticles with covalently attached chemical sensor molecules can be added to a container, such as a glass vial, and then optionally added with co-solvent(s) and/or buffer system. The mixture may be thoroughly stirred with a stirrer, such as a magnetic stirrer, for a first period of time. The first period of time may be, for example, about 15 minutes to 1 hour, 20 minutes to 45 minutes, or 30 to 40 minutes. After mixing, the hydrophobic matrix phase precursor may be added to the solution and the suspension stirred for a second period of time. The second period of time may be about 30 minutes to 5 hours, 1 hour to 4 hours, or 2 to 3 hours. Subsequently, a nonionic surfactant system may be added. The addition may be accomplished, for example, by dissolving the surfactant(s) in a small amount of an organic compound such as ethyl acetate. The mixture or dispersion comprising the solvent may be stirred for a third period of time. The third period of time may be about 5 to 30 minutes, 10 to 25 minutes, or 15 to 20 minutes. Subsequently, a crosslinking agent and a small amount of inhibitor may be added. The dispersion may be stirred for a fourth period of time. The fourth period of time may be about 30 minutes to 3 hours, 45 minutes to 2 hours, or 1 to 1.5 hours. Subsequently, the catalyst may be added, and the mixture may be stirred for a fifth period of time. The fifth period of time may be about 2 to 10 minutes, 5 to 7 minutes, or 3 to 6 minutes. Thereafter, the dispersion may be cast onto a film to form a chemical sensor layer. The film may be a transparent film, such as a transparent PET layer. The casting may be performed with a blade coater or another suitable tool. The resulting chemical sensor layer may be stored for a sixth period of time to achieve complete or substantially complete polymerization of the matrix phase. The sixth time period may be, for example, about 6 to 18 hours, 10 to 15 hours, or 12 to 14 hours. Storage may be provided under ambient conditions, such as ambient temperature and humidity.

Advantages of the chemical sensor described herein include the ability to measure in real time. "real-time" refers to the ability to perform a measurement or analysis, and the results are available almost immediately or in a very short time after the measurement or analysis is performed. The real-time sensor, device or system described herein has the advantage of providing results at the measurement site in a very short time. Real-time may involve seconds to minutes.

In addition, typical crown ether based sensor molecules participate in about 50-100ppm NH in the absence of co-solvent(s), typically due to the Kd of the sensor molecule being 80ppm ₄ ⁺ Binding reactions within the scope. The chemical sensor disclosed herein promotes the hydrophilic environment necessary for the PET effect and ensures that the measurement range moves down to about 0-5ppm without causing structural changes in the chemical sensing molecules. The resulting measurement range is thus much lower.

Although the chemical sensor 100 described herein focuses on the detection of ammonia, the principles of the chemical sensor 100 may be applied to different related analytes. Chemistry comprising a hydrophobic matrix 102 containing microparticles 104 containing sensing molecules 106, further comprising a surfactant system 108 and optionally a buffer system 114 and/or a co-solvent 118 The optical sensor may be adapted to detect, measure, and/or monitor various analytes in the medium as described herein. The chemistry of the chemical sensor 100 or portions thereof may differ from that described herein based on the type of aqueous medium, sample, analyte. Non-limiting exemplary analytes to be detected by the chemical sensors described herein may include toxic ions, such as Pb, as, cd, cr; ions responsible for "hard water", such as Mg and Ca; sulfur-containing compounds such as H ₂ S and H ₂ SO ₄ The method comprises the steps of carrying out a first treatment on the surface of the Containing carbon compounds, e.g. CO ₂ And formic acid (HCOOH).

The analyte may be part of an aqueous medium or an aqueous sample. The term "sample" is used in a broad sense to include a small amount of test medium intended to demonstrate the appearance of the entire test medium, as well as a larger volume of test medium. The sample includes the analyte and the remainder of the sample, also referred to as the sample matrix. The chemical sensors disclosed herein are configured or structured to allow access of analytes to the chemical sensing molecules, but to prevent entry of sample matrices into the chemical sensing molecules.

The various samples including the relevant analytes may differ from one another due to the environment from which the samples are derived. For example, individual samples may differ from one another in their biological, biochemical, chemical, and/or physical properties, such as pH, temperature, alkalinity, suspended solids, salinity, dissolved gases, and the like.

In one non-limiting example, the analyte may be an aquaculture analyte or an analyte present in an aquaculture sample. The analyte is to be detected by the aquaculture fluorescent-based chemical sensor described herein. The aquaculture sample may be derived from an aquaculture environment or medium such as aquaculture of fish, crustaceans, mollusks and the like. Thus, an aquaculture sample may contain biological, biochemical, chemical and/or physical parts typical of the aquaculture industry. The biological fraction may include plankton, fish waste, the presence of inedible food. The chemical moiety may comprise a pH between about 6.5 and 9.0 (if the aquaculture farm is healthy) or a different pH (if the farm pH needs to be improved), dissolved gases such as oxygen, carbon dioxide, nitrogen, ammonia, at least 5ppm dissolved oxygen, about 0p for healthy aquaculturepm to 5-15ppm CO ₂ The content is as follows. The physical portion may include clay particles or the like as suspended solids.

In another non-limiting example, the analyte may be an agricultural environmental analyte or an analyte in an agricultural environmental sample. The agricultural environmental sample may be a sample of aqueous medium derived from a farm location. The agricultural environmental sample may be a sample from agricultural runoff or a sample from a source of water for use as drinking water for farm animals. The farm may be a farm where livestock such as cattle, sheep, horses, goats, poultry such as chickens, geese, ducks, turkeys, pigs, horses or other animals are raised. Agricultural environmental samples may contain biological, biochemical, chemical and/or physical parts typical of land agriculture, including agricultural contaminants. Agricultural contaminants may include nutrients such as nitrogen, phosphorus, pesticides, herbicides, insecticides, fungicides, ammonia, bacteria, and the like.

The analyte may be a manufacturing analyte or an analyte present in a manufacturing sample. Manufacturing samples may include biological, biochemical, chemical, and/or physical portions typical of a particular manufacturing process conducted at a facility such as a factory. An exemplary facility may be a meat processing plant or slaughterhouse. Contaminants may include nitrates, nitrites, ammonia, fecal coliform, byproducts of the disinfection process such as chlorine, and the like.

The analyte may be a wastewater analyte or an analyte present in a wastewater sample. The wastewater sample may be an industrial or domestic wastewater sample. The wastewater sample may include biological, biochemical, chemical, and/or physical portions of the wastewater typical, including, but not limited to, organic matter and sulfide compounds. Samples of wastewater from the petroleum industry may include petroleum, fuel oil, and the like. The wastewater sample from the chemical plant may include carbonates, hydroxides, sand, organic compounds, salts of acids such as sulfuric acid or hydrochloric acid. The wastewater sample may originate from a facility or surface wash and include acids, ammonia, fluorides, nitrites, hexamethylenetetramine, sulfates, arsenic, vanadium, and the like.

The analyte may be a drinking water analyte or an analyte present in a drinking water sample. The potable water sample may comprise a fresh water or reservoir water sample for human or animal consumption. The drinking water sample may include biological, biochemical, chemical and/or physical parts typical of drinking water, such as microorganisms, toxins produced by bacteria, nitrogen, salts, ammonia, pesticides, metals, pharmaceutical components, and the like.

The analyte may be a bodily fluid analyte or an analyte present in a bodily fluid. Exemplary bodily fluid samples may be blood, plasma, urine, sweat, saliva, mucus, and the like. The body fluid sample may be derived from a human or animal. Body fluid samples may include biological, biochemical, chemical, and/or physical portions typical of an individual body fluid, including water, salts, proteins (e.g., enzymes such as amylase), ammonia, sugar, urea, uric acid, erythrocytes, leukocytes, platelets, electrolytes (e.g., potassium, phosphorus), and the like.

The analyte may be an aqueous analyte from an aqueous medium to be reprocessed or converted for further use, or an analyte from a sample containing the same. The reprocessed sample may include a recycled water sample, a brackish water sample, or a seawater sample.

Chemical sensors can be used to indicate ammonia, measure NH ₃ /NH ₄ ⁺ Content and/or monitoring in various environments. Chemical sensors can be used to indicate in real time ammonia in various aqueous media including fresh water, brackish water, sea water, recycled water, reservoir water, wastewater in water treatment facilities or processing facilities, body fluids, animal fluids, blood, and the like. The chemical sensor may be used in aquaculture, such as farmed fish, such as salmon, trout, crustaceans, such as shrimp, lobster, crab, crayfish, mollusks, such as clams, oysters, mussels, scallops, and the like, or combinations thereof. Aquaculture involves the cultivation of fresh water and brine populations under controlled conditions and can be contrasted with commercial fishing, which is the capture of wild fish. Chemical sensors may be used to indicate and/or monitor the aquatic health of the reservoir. The chemical sensor may also be used to detect ammonia in drinking water, wastewater, treated water, sewage, household wastewater, and municipal water sources. Chemical sensors can be used in agriculture, such as animal farming. Chemical sensors may be used in industrial environments such as chemical plants, farm animal processing plants, and the like.

Examples

Through the upper partThe ammonia chemical sensor made by the method and comprising tris buffer and glycerol co-solvent was tested in titration experiments using seawater as the aqueous medium. Real-time NH in seawater at a concentration in the range of 0-5ppm ₃ The results of the sensing are shown in fig. 5. It can be seen that fig. 5 shows a linear trend that increases in the range of 0-5 ppm.

In another embodiment, the chemical sensor 100 may be incorporated into a device configured to detect an analyte. The device may be an optical device or an optical system.

Typically, optical systems designed for analyte identification involve complex arrangements, but suffer from a number of drawbacks. For example, many optical systems strive to provide and preserve a sufficient amount of light, a sufficiently strong detection signal, and a loss of sensitivity.

The optical system includes, for example, an optical chemical sensor system utilizing fluorescence. Fluorescence-based sensing of analytes requires minimal irradiance with the greatest signal as strong and noiseless as possible. If the irradiance of the input light is too strong, it contributes to degradation of the chemical sensor. Irradiance can photobleach a molecule by causing unwanted side reactions to destroy the ability of the molecule to fluoresce. In addition, hydrolytic or chemical stresses may lead to failure such that the sensor phase from the membrane degrades. As a result, the sensor molecules or particles may be stripped from the sensing layer to reduce the total concentration of the sensor molecules in the optical path and reduce the output signal and impair calibration.

Some optical systems attempt to overcome the disadvantages by introducing signal enhancement elements, such as fiber optic cables for signal amplification. Other systems may include multiple detectors. Some systems also use waveguides for optical transmission. All of these components make the conventional system more complex, expensive and sensitive to transportation. Thus, the optical system is quite large in size and is traditionally stationary.

There remains a need for an optical analytical detection system that is relatively inexpensive, portable, and capable of withstanding a variety of environments, including corrosive environments associated with the aqueous medium being tested.

In one or more embodiments, an analytical optical detection system is disclosed. The system may be designed as a portable or point-of-use system. The term portable and point of use relates to systems that are not limited to a single location (e.g., laboratory), systems that do not require a table or another work surface to be secured in a laboratory, building or vehicle, systems that can be carried to and used in the field of testing. Portable or point-of-use systems can be easily transported from one location to another. Portability makes the system suitable for a variety of applications and sites. Portability also enables faster and more economical analysis than conventional systems, as analysis can be performed at the site where the results are needed, rather than transporting the sample to a laboratory.

The portable system is designed to analyze one or more analytes. An exemplary analyte may include ammonia. Other analytes, particularly those mentioned above, are contemplated. The system may thus be an ammonia analysis system. Non-limiting examples of the systems 200, 200' are shown in fig. 6 and 7. The system 200, 200' may be incorporated into a device, non-limiting examples of which are shown in fig. 8 and 9.

Based on the type of analyte and sample, the optical systems and sensing devices disclosed herein can include structural differences to reflect the environment in which the optical systems and sensing devices are used. For example, housing of aquaculture chemical sensors and sensing devices for aquaculture environments/analytes are manufactured to be resistant to aquaculture environments. One example of such a feature may include a waterproof, corrosion-resistant housing and/or seals, gaskets that prevent seawater from entering the optical system.

The optical system 200 depicted in fig. 7 includes a light source 202. The light source 202 may be an LED such as a blue LED, a laser, a modulated lamp, or a modulated light device. The light source 202 may be a modulated LED light source 202. The light source 202 may be a direct optical modulator. The light source 202 emits light having a wavelength that is dependent on or responsive to the excitation wavelength of the chemical sensors included in the system 200. Non-limiting exemplary wavelengths may be about 450 to 490, 460 to 480, or 470 to 475nm. Other wavelengths are contemplated. The wavelength emitted by the light source 202 may be a first wavelength. The light source 202 may be a monochromatic light source. The light source 202 may be an excitation source. The light source 202 is at a specific frequency (f _m ) Modulated to excite lightIs modulated. The modulated excitation intensity is generated at the chemical sensor at the same frequency (f _m ) Modulated transmission. The modulated light source 202 generates a light beam that is transmitted through free space. Light therefore does not propagate through optical waveguides such as optical fibers.

The system 200 further includes a lens 204. The lens 204 may be a collimating lens or collimator. Collimation is the process of precisely aligning light or particles in a parallel fashion. The collimating lens 204 may ensure that the incident light has minimal diffusion while propagating. The lens 204 may be an aspherical condenser lens. The lens 204 may include a diffuser. The lens 204 is configured to collimate and/or diffuse light from the light source 202. Lens 204 collimates the beam to maximize the beam diameter of the excitation light on the chemical sensor included in system 200. A lens 204 is arranged downstream of the light source 202. The lens 204 may be located near the light source 202.

The system 200 may further include one or more optical filters. The one or more filters may be color filters. One exemplary optical filter may be the first optical filter 206. The first filter 206 may be an excitation filter. Excitation filter 206 may limit irradiance to the spectral window that causes fluorescence. A filter 206 may be placed downstream of the lens 204 and the light source 202. A filter 206 is disposed between the lens 204 and the mirror 208. In one or more embodiments, the filter 206 is omitted.

After lens 204 and/or filter 206, system 200 includes mirror 208. The mirror may be a dichroic mirror. Mirror 208 may be a high-pass or long-pass dichroic mirror or beam splitter. Dichroic mirrors allow light of a particular wavelength(s) to pass through, while light of other wavelength(s) is reflected.

After passing through lens 204 and/or excitation filter 206, the excitation light is directed to dichroic mirror 208. The light is reflected downward at an angle to the chemical sensor 210. The angle of reflection may be 45 degrees. The chemical sensor 210 may be the chemical sensor 100 described above and shown in fig. 3A-4.

The chemical sensor 210 may be applied to the film(s) or layer(s). The film(s) or layer(s) may include dark portions, such as including carbon black, or a layer that prevents ambient light from entering the optical system 200. The film(s) or layer(s) may allow water to enter the chemical sensing portion of chemical sensor 210. The chemical sensor 210 is in contact with the liquid medium to be analyzed. The chemical sensor 210 reacts with the medium and if the analyte is present in the medium, the chemical sensor 210 causes fluorescence when the chemical sensing molecule reacts with the analyte. The chemical sensor 210 may generate fluorescence that is proportional to the concentration of the analyte in the medium.

The fluorescence generated by the chemical sensor has a different wavelength than the excitation light that reaches the chemical sensor by reflection at the mirror 208. The excitation wavelength is thus very different from the detection wavelength. The fluorescence is thus not reflected by dichroic mirror 208, but rather passes through dichroic mirror 208 and passes through dichroic mirror 208 to detection/light detection portion 212 of system 200 as the fluorescence travels upward. Exemplary detection wavelengths may be about 520 to 550nm, 525 to 545, or 530 to 535nm. Other wavelengths are contemplated. The fluorescent light may be light having a second wavelength. The second wavelength is different from the first wavelength.

The detection portion 212 may include a second filter 214. The second filter 214 may be an emission filter configured to reject any excitation light. The second filter 214 may be a detection filter. The detection filter may limit detection of the excitation signal, reduce noise, or both. The filter 206 may be located between the mirror 208 and the second lens 216.

The system 200 includes a second lens 216. The lens 216 may be an asymmetric lens. The second lens 216 may be a plano-convex lens. The plano-convex lens is planar on one side and curved outwardly on the other side. The plano-convex lens is configured to focus parallel rays of light to a single point. The lens 216 may collect light. The lens 216 may focus the fluorescence onto the photodetector 218. Lens 216 is located upstream of filter 206, mirror 208, and downstream of photodetector 218.

The photodetector 218 is configured to convert visible photons into electrical current. The photodetector 218 may be a photodiode or a phototransistor. Photodiodes are semiconductor devices that convert light into current. A current is generated when photons are absorbed in the photodiode. A phototransistor is a semiconductor device configured to sense the light level and vary the current flowing between the emitter and the collector according to the light level it receives. The photodetector 218 may include one or more filters, built-in lenses, and the like. The system 200 may include a single photodetector 218.

The system 200' shown in fig. 7 may include the same components as the system 200, but further includes an electrical device or electronic system 220. The electrical device 220 may include one or more controllers. The electrical device 220 may be a Printed Circuit Board (PCB) 220. The electrical device 220 may include one or more microprocessors, timing circuits, electrical or electronic components, conductive tracks, conductive pads, data registers, and/or other components capable of performing data processing, signal amplification.

The electrical device 220 is configured or programmed to control the light source 202, receive an input, such as a detection signal from the photodetector 218 and/or the photodetection portion 212, provide an input to one or more portions of the system 200, provide an output to another device, or a combination thereof. The input provided by the electrical device to the light source 202 may include commands to start analysis, stop analysis, start light excitation, stop light excitation, etc., or a combination thereof. The input that the electrical device may receive from the photodetector 218 may include a signal. The output provided by the electrical device may be digital and/or data associated with the analyte, its quantity, or other information related to the analysis.

The system 200 and/or 200' may also include one or more additional devices, such as differential amplifiers, high pass filters, and the like. The additional means may filter out DC and low frequency components of the light. The additional means may only allow the modulated high frequency emissions to pass through and be amplified. This ensures that any ambient or stray light picked up by the photodetector is not amplified. This results in an improved signal-to-noise ratio of the fluorescent signal generated by the chemical sensor 210.

The systems 200 and/or 200' may be compatible with a variety of devices and systems. For example, the system may be compatible with a computer and include a transducer that may be inserted into one or more devices including the computer. The system may be wired or wireless, with signals being communicated from the system 200, 200' via bluetooth, wiFi, zigby, GSM, RFID, or another form of communication.

The systems disclosed herein may be incorporated into a housing. One non-limiting example of a housing is schematically shown in fig. 7. An alternative view of the housing is shown in fig. 8. The housing 250, the systems 200 and/or 200', and additional elements disclosed herein may form an analysis or sensing apparatus 300.

The housing 250 may be compact to enable portability of the analysis device 300. The housing 250 may be modulated, molded, injected, extruded, 3D printed, or otherwise molded around one or more components of the device 300. The housing 250 is designed to carry, protect, or enclose the optical and electrical components of the device system 200 and/or 200' and the device 300.

The housing 250 may have one or more layers. For example, the housing 250 may have a first or inner layer 252 that surrounds the system 200' (with or without the electrical device 220). The first layer 252 may form an interior portion or layer of the housing 250. The housing 250 may also include an outer layer 254 that encloses all of the internal components, including the system 200' with the optical components and the electrical device 220 together. The optical components and electrical devices may be mounted or otherwise attached in the housing 250. The attachment may be permanent or temporary in order to replace the assembly.

The outer layer 254 may be waterproof and corrosion resistant. The water-resistant feature allows the system 200, 200' and/or the device 300 to be submerged in an aqueous medium. For example, the outer layer 254 may be made of a corrosion and water resistant material. Alternatively, a coating of a desired quality may be applied to the outer layer 254. A non-limiting exemplary coating may be a hydrophobic coating. The outer layer 254 and the housing 250 may be waterproof according to IP67, reference to the ingrasprotection code, sometimes referred to as InternationalProtection Code, IEC standard 60529, which classifies and rates the degree of protection provided by mechanical and electrical housings from intrusion, dust, accidental contact and water. IP67 rating means that the devices disclosed herein can fall into a body of water up to 1 meter deep for half an hour without causing a change in the function or durability of the device.

Although first layer 254, housing 250, or both include the optical components of system 200 or 200', chemical sensor 210 is housed separately. The housing 250 is waterproof to protect the optical and electrical components while the chemical sensor 210 is in contact with the medium to be tested. The water-resistant feature allows the system 200, 200' and/or the device 300 to be submerged in an aqueous medium.

The chemical sensor 210 may be disposed in the compartment 260. The compartment 260 may be a cartridge, bag, cylinder, receptacle, vessel, housing, or container that is attached or attachable to the housing 250. The connection between the housing 250 and the compartment 260 is such that the integrity and waterproof quality of the housing and its internal components is not compromised. The connection may include one or more seals 262, such as one or more O-rings, gaskets, or combinations thereof, that ensure a watertight seal. One non-limiting example of a compartment 260 is shown in fig. 9.

The compartment 260 may have an upper portion 266 and a lower portion 268. The upper portion 266 may be permanently or temporarily attached to the housing 250 and to the lower portion 268. The upper portion 266 may house the seal(s) 262 and the chemical sensor 210. The lower portion 268 may be attached to the upper portion 266. The lower portion 268 may have an opening and closing mechanism 270 that allows the test medium to enter the device. The mechanism 270 may have, for example, one or more slidable portions 272.

The housing 250, the first layer 252, the second layer 254, the compartment 260, or a combination thereof may be made of the same or different materials. For example, the material may comprise steel, such as stainless steel, plastics, such as thermoplastics or thermosets, composites, ceramics, or combinations thereof. The housing 250, the first layer 252, or both may be black.

As can also be seen in fig. 8, leads/plugs 222 from electrical device 220 may extend from housing 250 to connect electrical wires, such as data cables.

The devices and systems disclosed herein may be free of fiber optic cable(s), waveguide(s), secondary detector(s), and/or objective lens(s) configured to focus light. Thus, the system and thus the device is less complex than conventional systems, more economical, and can be incorporated into devices of smaller size than conventional optical analysis systems. The present disclosure is not limited to a range of sizes, but the device and other devices in which the system may be employed may have sizes such that the device may be portable and/or handheld.

The systems and devices disclosed herein may be used as analytical optical instruments for the complex media described above in the above-described environments to identify, monitor, quantify, and/or qualitatively analyze the analytes described herein.

In one or more embodiments, methods of using the disclosed chemical sensors, systems, and devices are disclosed. The method may include contacting the chemical sensor with a medium/sample to be tested. The chemical sensor may prevent the inflow of one or more types of interfering ions upon contact with the medium/sample. The method may include allowing the analyte to flow into the matrix such that the particles carrying the chemical sensing molecules and the surfactant system embedded in the matrix may react with the analyte to generate fluorescence upon photoexcitation.

The method may include initiating excitation from a light source. The method may include transmitting the light beam through free space. The method may include transmitting the light beam via a lens and/or a first filter. The method may include reflecting light onto the chemical sensor via a mirror, such as a dichroic mirror.

The method may further comprise generating fluorescence by reaction of the analyte with the chemical sensing molecule. The method may include transmitting the fluorescent light to the photodetector via the mirror, the second filter, and the second lens. The method may further comprise converting the visible photons into a current or signal in the photodetector.

The method may further include modulating, collimating, reflecting, transmitting, filtering, expelling, and/or focusing excitation light or fluorescence, reducing noise, or a combination thereof by one or more elements of the disclosed system.

The method may also include forwarding or transmitting the electrical signal to another device via an electrical apparatus, an electronic system, or wirelessly. The method may include controlling the optical system and/or apparatus via an electrical device. The method may include controlling or commanding, via the electrical device, the light source and/or one or more elements of the system and/or apparatus. The method may include transmitting the electrical signal wirelessly or via one or more wires to a different device, system or database.

The processes, methods, or algorithms disclosed herein may be communicated to or executed by a processing device, controller, or computer, which may include any existing programmable or dedicated electronic control unit. Similarly, the processes, methods, or algorithms may be stored as controller or computer executable data and instructions in a number of forms including, but not limited to, information permanently stored on non-writable storage media such as ROM devices, and information variably stored on writable storage media such as floppy disks, magnetic tape, CDs, RAM devices and other magnetic and optical media. The process, method, or algorithm may also be implemented in a software executable object. Alternatively, the process, method, or algorithm may be embodied in whole or in part using suitable hardware components, such as Application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs), state machines, controllers or other hardware components or devices, or combinations of hardware, software, and firmware components.

The following applications are relevant to the present application: U.S. patent application Ser. No. ___ (RBPA 0327PCT, RBPA0329PCT and RBPA0330 PCT) filed on month 2 and 10 of 2021, which are incorporated herein by reference in their entirety.

While exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As noted above, features of the various embodiments may be combined to form further embodiments of the present disclosure that are not explicitly described or illustrated. While various embodiments may have been described as providing advantages in terms of one or more desired features or over other embodiments or prior art embodiments, one of ordinary skill in the art will recognize that one or more elements or features may be sacrificed to achieve the desired overall system properties, depending on the specific application and implementation. Such attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, availability, weight, manufacturability, ease of assembly, and the like. Thus, if any embodiment is described as being less desirable in one or more features than other embodiments or prior art embodiments, such embodiments are not outside the scope of the present disclosure and may be desirable for a particular application.

Claims

1. An optical system, comprising:

a fluorescent-based chemical sensor configured to emit fluorescence when the chemical sensing molecule reacts with the aquaculture analyte and when excited by light;

a modulated light source configured to generate a light beam having a wavelength responsive to an excitation wavelength of the chemical sensor, the light being transmitted through free space;

a collimating lens configured to collimate and diffuse the modulated light;

a dichroic mirror arranged to reflect the modulated light onto the chemical sensor and to transmit the light re-emitted from the chemical sensor onto the photodetector; and

a lens upstream of the photodetector configured to focus the re-emitted light onto the photodetector,

the optical system is enclosed in a waterproof, corrosion resistant housing.

2. The optical system of claim 1, wherein the aquaculture analyte is ammonia.

3. The optical system of claim 1, wherein the optical system is a real-time analysis sensor.

4. The optical system of claim 1, wherein the lens is an asymmetric lens configured to focus the re-emitted light before the re-emitted light enters the photodetector.

5. The optical system of claim 1, further comprising one or more color filters.

6. The optical system of claim 1, wherein the optical system is housed in a portable aquaculture aqueous media sensing device.

7. A real-time ammonia sensing device for aquaculture aqueous media comprising:

an optical system having

A light source configured to generate a light beam having a first wavelength to be transmitted through free space;

a collimator configured to collimate the light,

a dichroic mirror configured to reflect collimated light of a first wavelength onto a fluorophore-containing chemical sensor configured to react with an analyte in an aquaculture aqueous medium sample and to transmit light of a second wavelength re-emitted from the chemical sensor onto a photodetector; and

an electronic system having a microprocessor programmed to receive a signal corresponding to light re-emitted from a photodetector and provide information in real time based on the signal.

8. The sensing device of claim 7, wherein the first wavelength is an excitation wavelength of the chemical sensor.

9. The sensing device of claim 7, wherein the second wavelength is different from the first wavelength.

10. The sensing device of claim 7, wherein the optical system and the electronic system are sealed from contact with the aquaculture aqueous medium.

11. The sensing device of claim 7, wherein the device is portable.

12. The sensing device of claim 7, wherein the device comprises a waterproof, corrosion resistant housing.

13. The sensing device of claim 7, wherein the chemical sensor is housed in a compartment accessible to the aquaculture aqueous medium.

14. An aquaculture medium ammonia sensing device comprising:

a housing, the housing comprising

A modulated light source configured to generate a light beam having a first wavelength, the first wavelength being dependent on an excitation wavelength of the fluorescent-based chemical sensor, the light being transmitted through free space;

a collimating lens configured to collimate and diffuse the modulated light;

a dichroic mirror configured to reflect the modulated light onto the chemical sensor and transmit the light re-emitted from the chemical sensor onto the photodetector; and

a lens upstream of the photodetector configured to focus the re-emitted light onto the photodetector; and

a compartment attached to the housing and comprising a fluorescent-based chemical sensor configured to re-emit light when the chemical sensing molecule reacts with ammonia in the aquaculture aqueous medium sample.

15. The device of claim 14, wherein the housing is waterproof and corrosion resistant.

16. The device of claim 14, wherein the compartment is configured to enable the chemical sensor to be in contact with the aquaculture aqueous medium.

17. The apparatus of claim 14, wherein the housing further comprises an electronic system comprising a microprocessor programmed to receive signals from the photodetector.

18. The device of claim 17, wherein the microprocessor is programmed to communicate with another electronic device.

19. The device of claim 14, wherein the device is a portable device.

20. The device of claim 14, wherein the device is a real-time aquaculture ammonia sensor.