JP7273703B2 - sensor - Google Patents

Description

The present invention relates to sensors with receptors.

Sensors generally have a sensing portion (receptor) that enables highly sensitive and selective detection of the analyte of interest. A wide variety of substances such as self-assembled membranes, monolayers, DNA/RNA, proteins, antigens/antibodies, and polymers are used as receptors. Due to the recent development of AI and IoT in the olfactory/gas sensor field, new applications are expected in the future.

In Patent Document 1, a porous material or a granular material is coated on a sensor body of a type that detects a physical parameter, and the specimen molecules are adsorbed by the porous material or the granular material. A sensor for detecting molecules is described.

In Patent Document 2, a gas sensitive part containing cerium oxide as a main component and a detection electrode for detecting an electrical resistance value of the gas sensitive part are provided, and at least one of an oxygen-containing organic compound and a sulfur-containing compound is used. A gas sensing element for sensing is described.

Patent document 3 has a sensitive part made of a sensitive material in which a water-insoluble polymer material and a water-soluble polymer that is responsive to humidity are mixed, and measures a change in conductivity of the sensitive part. Moisture sensitive sensors are described that detect humidity or condensation by

WO2016/121155 JP 2010-002335 A JP-A-11-101766

Although the technology described in Patent Document 1 achieves high sensitivity, selectivity, and stability, the electrical signal is greatly attenuated except in a dry atmosphere, and the environment in which it can be used as an olfactory sensor is greatly restricted.

The technology described in Patent Document 2 achieves highly sensitive, selective, and stable detection of low-concentration oxygen-containing organic compounds and sulfur-containing compounds, while the gases to be detected are limited to oxygen-containing organic compounds and sulfur-containing compounds. It is

The technique described in Patent Document 3 provides a moisture-sensitive sensor that is suitable for living organisms and suitable for both humidity and dew condensation, but cannot detect gases other than humidity.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to enable measurement of highly hydrophilic gases such as ethanol and aldehyde with high sensitivity even under humid conditions. Another object of the present invention is to provide a sensor capable of continuous measurement without deterioration of the receptor even after reflow treatment and long-term use.

In order to solve the above-mentioned problems, the inventors of the present application have made earnest studies and repeated experiments.

That is, the present invention includes the following aspects.
[1]
A sensor having a receptor layer comprising an organic-inorganic hybrid,
The receptor layer has a structure containing units represented by the formula RSiO _3/2 (wherein R represents an organic functional group),
The organic-inorganic hybrid includes a first component having a weight average molecular weight of 800 to 10000 and a second component having a weight average molecular weight of 30000 to 2000000,
The sensor, wherein the peak area of the second component measured by GPC is 0.01% to 55% of the total peak area of the first component and the second component.
[2]
The sensor of [1], wherein the second component is a filler.
[3]
The sensor of [2], wherein the filler comprises a metal oxide.
[4]
The sensor of any one of [2] or [3], wherein the filler comprises silica.
[5]
The sensor according to any one of [2] to [4], wherein the shape of the filler is spherical or chain.
[6]
The sensor according to any one of [1] to [5], wherein the organic functional group contains at least one aromatic ring structure.
[7]
The sensor of [6], wherein the aromatic ring structure of the organic functional group is directly bonded to a Si atom.
[8]
The sensor of [6] or [7], wherein the organic functional group is a copolymer structure of an aromatic ring structure and a non-aromatic ring structure.
[9]
The sensor of [8], wherein the non-aromatic ring structure comprises one selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, a boron atom, and a phosphorus atom.
[10]
The sensor according to any one of [1] to [9], wherein the organic-inorganic hybrid has an organic component content of 75% by weight or less.
[11]
The sensor according to any one of [1] to [10], wherein the maximum thickness of the receptor layer is 30 μm or less.
[12]
The sensor according to any one of [1] to [11], wherein the sensor is a surface stress sensor.

According to the present invention, highly hydrophilic gases such as ethanol and aldehyde can be measured with high sensitivity even under humid conditions. It is possible to provide a sensor that can continuously measure without deterioration of

An example of an optical micrograph of a chip coated with a receptor is shown. 1 shows the results of GPC in Example 1. FIG. 1 shows an image and film thickness distribution obtained by observing the receptor of Example 1 with a confocal microscope. The response of Example 1 to ethanol at 0% and 30% humidity is shown. 2 shows the results of GPC in Example 2. FIG. Responsiveness to ethanol at humidity of 0% and 30% of Comparative Example 3 is shown.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.

The sensor of this embodiment has a receptor containing an organic-inorganic hybrid, and the _organic -inorganic hybrid has a structure (hereinafter , Also referred to as “a structure represented by RSiO _3/2 ”), the organic-inorganic hybrid has a first component having a weight average molecular weight of 800 to 10,000 and a second component having a weight average molecular weight of 30,000 to 2,000,000. wherein the peak area of the second component measured by GPC is 0.01% to 55% of the total peak area of the first component and the second component. Since the receptor is configured in this way, the sensor of this embodiment can measure highly hydrophilic gases such as ethanol and aldehyde with high sensitivity even under humid conditions. After reflow treatment, measurement can be continued without deterioration of the receptor even after long-term use.

The sensor of this embodiment includes, but is not limited to, a sensor body of a type that detects physical parameters, for example. Physical parameters include, but are not limited to, surface stress, stress, force, surface tension, pressure, mass, elasticity, Young's modulus, Poisson's ratio, resonance frequency, frequency, volume, thickness, viscosity, density, magnetic force, magnetism quantity, magnetic field, magnetic flux, magnetic flux density, electrical resistance, electrical quantity, permittivity, power, electric field, charge, current, voltage, potential, mobility, electrostatic energy, capacitance, inductance, reactance, susceptance, admittance, impedance, conductance , plasmons, refractive index, luminosity and temperature and various other physical parameters. The sensor of the present embodiment is, for example, a sensor in which a receptor receptor layer (sometimes referred to as a “sensitive film” in this technical field) is provided directly on the sensor body. That is, the sensor of the present embodiment can detect, by the sensor body, changes in physical parameters caused by the adsorption of analyte molecules on the receptor layer. As described above, the sensor body that can be used in the present embodiment is particularly useful if it detects a change induced in the receptor by the receptor layer arranged on its surface adsorbing the substance to be detected. Not limited.

When the sensor of the present embodiment is applied to, for example, a surface stress-type olfactory sensor, the receptor sensitive membrane covering at least a part of the surface of the sensor body adsorbs the substance to be detected, thereby The main body outputs a signal by detecting the induced stress change.

Also, another type of sensor body may be applied, for example, a QCM device. The QCM device measures minute changes in mass by using the property that when a substance is adsorbed on the electrode surface of a crystal oscillator to which an alternating electric field is applied, the resonance frequency decreases according to the mass and viscoelasticity of the adsorbate. It is a mass sensor and can be measured in-situ. When the sensor of this embodiment is applied as a QCM device, for example, by forming the receptor sensitive membrane in this embodiment on the surface of the electrode, the receptor detects the mass change caused by adsorbing the substance to be detected. Detected by the main unit and output a signal. Various conductive materials can be applied as the electrodes of the QCM. When the receptor in this embodiment is to have conductivity, the receptor can also be used as the electrode of the QCM.

In the present specification, the term "adsorption" is used to include a phenomenon in which the concentration of another substance (which becomes an adsorbate) increases compared to the surroundings at the interface of a certain object, and not only physical adsorption, It also includes chemisorption due to chemical bonding and biochemical action.

[Receptor]
Receptors in this embodiment include organic-inorganic hybrids. The organic-inorganic hybrid in this embodiment includes a structure represented by RSiO _3/2 from the viewpoint of sensitivity and stability in a humid environment, where R represents an organic functional group.

In this embodiment, the organic functional group preferably contains one or more aromatic rings (aromatic ring structure). When it contains an aromatic ring, the moisture resistance tends to be further improved. The aromatic ring is not particularly limited because it can be appropriately selected in consideration of the use of the sensor, etc. Examples include aromatic hydrocarbon groups such as phenyl group, naphthyl group, p-tolyl group and biphenyl group, 4-chlorophenyl group, 4-methoxyphenyl group, 4-aminophenyl group, substituted aromatic hydrocarbon groups such as pentafluorophenyl group, 3-furyl group, 3-thienyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, etc. and metallocenes such as a ferrocenyl group and the like. The organic functional group in the present embodiment may contain one of the aromatic rings described above, or may contain two or more of them.

In the organic-inorganic hybrid, between the aromatic ring and the silicon atom, an alkyl group (having 1 to 18 carbon atoms), an ether group, a carbonyl group, a carboxyl group, an amide group, a urethane bond, a urea bond, an imide group , An imine group or other spacer structure may be interposed, but from the viewpoint of responsive sensitivity, it is preferable that the aromatic ring is directly bonded to the Si atom in the organic-inorganic hybrid without interposing such a spacer.

From the viewpoint of achieving both humidity resistance and selectivity to various gas molecules, the organic functional group in the present embodiment preferably contains a copolymer structure of an aromatic ring structure and a non-aromatic ring structure.

In addition, from the viewpoint of responsiveness to highly polar gas and odor molecules, the organic functional group in the present embodiment includes a nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a boron atom. , and phosphorus atoms. Among these, from the viewpoint of stability, the organic functional group preferably contains a functional group containing one or more atoms selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, and a fluorine atom.

Specific examples of the organic functional group in the present embodiment are not limited to the following, but linear or branched hydrocarbon groups that may have substituents such as halogen atoms (e.g., 3-chloropropyl group, octyl linear or branched C _1-8 alkyl groups such as groups), alicyclic hydrocarbon groups optionally having substituents such as halogen atoms (e.g., C _5-6 cycloalkyl groups such as cyclohexyl groups), Aromatic hydrocarbon groups that may have substituents such as halogen atoms (e.g., phenyl group, pentafluorophenyl group, etc.), vinyl groups, allyl groups, (meth)acrylic groups, (meth)acryloyloxyalkyl groups ( (Meth)acryloyloxy C _1-3 alkyl groups such as (meth)acryloyloxypropyl groups), epoxy groups, glycidyloxyalkyl groups (e.g. glycidyloxy C _1-3 alkyl groups such as 3-glycidyloxypropyl groups) ), (epoxycycloalkyl)alkyl group (e.g., 2-(3,4-epoxycyclohexyl)ethyl group, etc.), hydroxy group, ether group, carbonyl group, carboxyl group, ester group, urethane group, urea group, mercapto group , mercaptoalkyl groups (e.g., mercapto C _1-3 alkyl groups such as mercaptopropyl groups), sulfide groups, amino groups (e.g., primary amino groups, secondary amino groups, tertiary amino groups), aminoalkyl groups (e.g., , amino C _1-3 alkyl group such as aminopropyl group), (aminoalkylamino)alkyl group (e.g., 3-(2-aminoethylamino)propyl group), imidazolyl group, imidazolylalkyl group (e.g., 3-( 2-imidazolin-1-yl)propyl group), alkylaminoalkyl group (e.g., 3-(dimethylamino)propyl group), amide group, heterocyclic aromatic group, oxime group, imide group, imine group, halogen group, A nitrile group, a phosphonic group, a phosphoric acid group and the like can be mentioned. Among these, from the viewpoint of availability, the organic functional group is a linear or branched hydrocarbon group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, and a substituent. Aromatic hydrocarbon group, vinyl group, allyl group, (meth)acryloyloxyalkyl group, glycidyloxyalkyl group, (epoxycycloalkyl)alkyl group, mercaptoalkyl group, aminoalkyl group, (aminoalkylamino ) is preferably one or more selected from the group consisting of an alkyl group, an imidazolylalkyl group, an alkylaminoalkyl group, and a hydroxy group. These functional groups are used singly or in combination of two or more.

The organic functional group is preferably an organic functional group derived from a silane coupling agent. Silane coupling agents include hydrolyzable metal oxides such as alkoxysilanes, acetoxysilanes and chlorosilanes. Among these, hydrolyzable metal oxides are preferably alkoxysilanes from the viewpoint of handleability and versatility of functional groups, and more preferably trifunctional alkoxysilanes from the viewpoint of reactivity.
Trifunctional alkoxysilanes may be copolymerized with mono-, di-, or tetra-functional alkoxysilanes, but from the viewpoint of increasing the Young's modulus of organic-inorganic hybrids and increasing their sensitivity, copolymerization with tetra-functional alkoxysilanes is preferred. is preferred.

As the trifunctional alkoxysilane, a silane coupling agent having an alkoxy group having a methoxy group, an ethoxy group, or an isopropoxy group can be used.
Commercially available aromatic silane coupling agents include phenyltrialkoxysilane, nitrobenzeneamidetrialkoxysilane, benzyltrialkoxysilane, 4-chlorophenyltrialkoxysilane, phenylaminopropyltrialkoxysilane, 4-aminophenyltrialkoxysilane, and naphthyl. trialkoxysilane, 4-methoxytrialkoxysilane, pentafluorophenyltrialkoxysilane, ferrocenyltrialkoxysilane, biphenyltrialkoxysilane, 3-furyltrialkoxysilane, 3-thienyltrialkoxysilane, 2-pyridyltrialkoxysilane, Examples thereof include 3-pyridyltrialkoxysilane, 4-pyridyltrialkoxysilane, and the like, but are not limited to these.

Commercially available non-aromatic silane coupling agents include 3-(2-aminoethylamino)propyltrialkoxysilane, 3-mercaptopropyltrialkoxysilane, vinyltrialkoxysilane, cyclohexyltrialkoxysilane, and 3-glycidyloxypropyl. trialkoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrialkoxysilane, 3-(dimethylamino)propyltrialkoxysilane, 3-(2-imidazolin-1-yl)propyltrialkoxysilane, 3-aminopropyl trialkoxysilane, 3-(methacryloyloxy)propyltrialkoxysilane, 3-(acryloyloxy)propyltrialkoxysilane, allyltrialkoxysilane, methyltrialkoxysilane, ethyltrialkoxysilane, propyltrialkoxysilane, butylalkoxysilane, hexyltrialkoxysilane, octyltrialkoxysilane, decyltrialkoxysilane, dodecyltrialkoxysilane, octadecyltrialkoxysilane, 3-ureidopropyltrialkoxysilane, cyclohexylaminopropyltrialkoxysilane, hexafluorophenyltrialkoxysilane, 3-chloro Propyltrialkoxysilane, 3-bromopropyltrialkoxysilane, 3-piperazinopropyltrialkoxysilane, 3-morpholinopropyltrialkoxysilane, 3-allylaminopropyltrialkoxysilane, norbornyltrialkoxysilane, piperidine Examples include, but are not limited to, nopropyltrialkoxysilane.

When two or more silane coupling agents are copolymerized, the ratio of the aromatic silane coupling agent and the non-aromatic silane coupling agent is preferably 1:10 to 1:5 in terms of molar ratio. from 1:5 to 1:1 from the point of view, and preferably from 1:1 to 10:1 from the point of suppression of reduction in signal intensity under humidity.

The organic functional groups in the sensor of this embodiment can be identified by subjecting the receptor on the sensor body to surface elemental analysis such as SEM-EDX, XPS, and ATR.

In the organic-inorganic hybrid of the present embodiment, the first component having a weight average molecular weight in terms of polystyrene of 800 to 10000 with an RI detector and the second component having a weight average molecular weight of 30000 to 2000000 are included to improve sensor sensitivity. can be made
The weight average molecular weight of the first component is preferably from 900 to 9000 from the viewpoint of ink applicability, and more preferably from 1000 to 8000 from the viewpoint of synthesis reproducibility.
The weight average molecular weight of the second component is preferably from 40,000 to 1,900,000 from the viewpoint of further improving sensitivity, and more preferably from 5,000 to 1,800,000 from the viewpoint of ink applicability.

As for the weight average molecular weight ratio of the first component to the second component, the signal intensity (area integration) of the second component is preferably 0.01% to 55% of the total area of all components in order to improve the sensitivity. , 0.05% to 50% is preferable from the viewpoint of ink applicability, and 0.1% to 45% is more preferable from the viewpoint of humidity resistance.

[Filler]
Preferably, the second component of the receptor in this embodiment is a filler. The use of a filler can improve the Young's modulus of the organic-inorganic hybrid and enhance the sensitivity. The filler in this embodiment is not particularly limited, and can be selected from various known fillers. Specific examples include, but are not limited to, polymer beads such as polystyrene, polymethyl methacrylate, and polyphenylene oxide, spherical particles such as acrylic latex, metal nitrides such as silicon nitride, silica, zirconia, titania, zinc oxide, and aluminum oxide. , metal oxides such as tin oxide, barium titanate, strontium titanate, complex metal compounds such as ITO, inorganic metal fillers such as gold, silver, copper, palladium, platinum, iron, aluminum, carbon nanotubes, graphene, carbon dots , and carbon black.

From the viewpoint of dispersibility and coatability, the filler in the present embodiment is preferably an inorganic filler. From the same viewpoint as above, in the present embodiment, metal compounds such as silica, zirconia, titania, and alumina, and inorganic metal fillers such as gold, silver, copper, palladium, platinum, iron, and aluminum are preferable, and moisture under humidity is preferred. Metal oxides such as silica and zirconia are more preferable because they are less affected by signal attenuation, and silica is more preferable from the viewpoint of economy. The inventors have found that, especially when silica is used, the attenuation of the response of common hydrophilic gases such as ethanol, acetaldehyde, etc. is significantly improved even in humid conditions. The reason for this is considered as follows, but it is not intended to be limited to the following. That is, since the hydroxyl group present in a state bonded to the skeleton of silica and the silicon atom is relatively hydrophobic compared to the hydroxyl group bonded to the titania skeleton or titanium atom of Patent Document 1, the hydrophobic interaction causes It is presumed that the adsorption inhibition of

The shape of the filler is not particularly limited, but from the viewpoint of availability, it is preferably spherical, rod-like, plate-like, fibrous, or a shape in which two or more of these are combined, and more preferably spherical or chain-like. be. The term "spherical" as used herein means not only a perfect sphere, but also a substantially spherical shape including spheroids, ovoids, and the like.

The size of the spherical filler is not particularly limited, but from the viewpoint of maintaining the dispersibility of the ink, that is, improving the coating properties of the ink jet, etc., the average primary particle size is preferably 100 μm or less, and the sensitivity is improved. It is more preferably 500 nm or less from the viewpoint of improvement, and further preferably 200 nm or less from the viewpoint of further reducing voids. Here, the average primary particle diameter means a number average value. The average primary particle size of 50 particles measured by the method using a scanning electron microscope as described in the Examples section of this specification, or by a method understood to be equivalent to this It is a numerical average value.

The chain-like filler preferably has a continuous chain-like structure. A structure (also referred to as a "pearl necklace-like" structure), or a structure in which a number of thread-like structures are not observed as individual continuous spheres but are entwined (also referred to as a "network-like" structure). is mentioned as a preferable example.

The filler that constitutes the continuous chain structure is generally assumed to be spherical, and it is not easy to define it by the primary particle size, but the chain width can be observed by transmission or scanning electron microscope observation. The chain width is 1 nm to 200 nm, preferably 1 nm to 100 nm from the viewpoint of increasing the surface area covered, and more preferably 1 nm to 85 nm from the viewpoint of gas responsive sensitivity. The average primary particle size of 50 particles measured by the method using a scanning electron microscope as described in the Examples section of this specification, or by a method understood to be equivalent to this Number average, defined as chain width.

Such a metal oxide as a filler can be produced by a sol-gel method using a metal oxide precursor having a tetrafunctional hydrolyzable group such as alkoxy or chloro, or a commercially available product can be used. can also Metal oxide precursors having a tetrafunctional hydrolyzable group include tetraalkoxysilane, tetrachlorosilane, tetraalkoxytitanium, tetraacetoxyzirconium and the like. These tetrafunctional hydrolyzable metal inorganic oxides may be copolymerized with trifunctional hydrolyzable metal oxides, and the shape can be obtained by adjusting the concentration, temperature, pH, water content, etc. of the reaction system. can be controlled. For example, when the filler is produced by emulsion polymerization, it is conceivable that a structure represented by RSiO _3/2 may be obtained on the filler side. shall be treated as an organic-inorganic hybrid in form.

Commercially available fillers that can be used include the LEVASIL series (manufactured by HC Starck Co., Ltd.), the Quartron PL series (manufactured by Fuso Chemical Co., Ltd.), the OSCAL series (manufactured by Catalysts and Chemicals Industry Co., Ltd.), and the like; Examples of powdery silica particles include Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50 (manufactured by Nippon Aerosil Co., Ltd.), Sildex H31, Sildex H32, Sildex H51, Sildex H52, Sildex H121, Same H122 (manufactured by Asahi Glass Co., Ltd.), E220A, E220 (manufactured by Nippon Silica Industry Co., Ltd.), SYLYSIA470 (manufactured by Fuji Silysia Co., Ltd.), SG flake (manufactured by Nippon Sheet Glass Co., Ltd.), etc., IPA- ST, IPA-ST-L, IPA-ST-ZL, ST-XS, ST-S, ST-30, ST-50T, ST-30L, ST-YL, ST-ZL, MP-1040, MP-2040, MP-4540M, ST-OXS, ST-OS, ST-O, ST-O-40, ST-OL, ST-OYL, ST-NXS, ST-NS, ST-N, ST-N-40, ST- CXS, ST-C, ST-CM, ST-AK, ST-AK-L, ST-AK-YL, OZ-S30K, SZ-S30K-AC, OZ-S30M, CELNAX CX-S505M, IPA-ST- UP, MEK-ST-UP, ST-UP, ST-PS-S, ST-PS-M, ST-OUP, ST-PS-SO, ST-PS-MO, ST-AK-PS-S, etc. (Nissan Kagaku Co., Ltd.), SRD-K, SRD-M,
SXR-CM, SZR-K, SZR-M (manufactured by Sakai Chemical Co., Ltd.). Examples of powdery fillers include Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50 (manufactured by Nippon Aerosil Co., Ltd.), Sildex H31, Sildex H32, Sildex H51, Sildex H52, and Sildex H121. H122 (manufactured by Asahi Glass Co., Ltd.), E220A, E220 (manufactured by Nippon Silica Industry Co., Ltd.), SYLYSIA470 (manufactured by Fuji Silysia Co., Ltd.), SG flake (manufactured by Nippon Sheet Glass Co., Ltd.), etc. can be done.

[Method for producing organic-inorganic hybrid]
Although the method for producing the organic-inorganic hybrid is not particularly limited, it is mainly produced using a sol-gel method. Specifically, a hydrolyzable silane compound (including a silane coupling agent) is treated by a sol-gel method under acidic and basic conditions in the presence of water to produce a condensate of the silane coupling agent, namely RSiO ₃ . Organic-inorganic hybrids containing structures represented by _/2 can be obtained.

From the viewpoint of being able to control the reaction rate of hydrolysis and condensation, it is more preferable to hydrolyze and condense the silane coupling agent and modify the surface in the presence of a catalyst.

Types of catalysts include acid catalysts and base catalysts. Acid catalysts include, for example, inorganic acids and organic acids. Examples of inorganic acids include, but are not limited to, hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, and boric acid. Examples of organic acids include, but are not limited to, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, and benzoic acid. acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, tartaric acid, citraconic acid, malic acid, glutaric acid, etc. is mentioned. Base catalysts include, for example, inorganic bases and organic bases. Examples of inorganic bases include, but are not limited to, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and cesium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide; alkali or alkaline earth metal carbonates such as lithium, potassium carbonate and sodium carbonate; metal hydrogencarbonates such as potassium hydrogencarbonate and sodium hydrogencarbonate; and the like. Examples of organic bases include, but are not limited to, trialkylamines such as triethylamine and ethyldiisopropylamine; N,N-dialkylaniline derivatives having 1 to 4 carbon atoms such as N,N-dimethylaniline and N,N-diethylaniline; pyridine derivatives optionally having an alkyl substituent having 1 to 4 carbon atoms, such as pyridine and 2,6-lutidine; and the like. These catalysts can be used singly or in combination of two or more.

It is preferable in terms of reaction efficiency to add an amount of catalyst that brings the pH of the reaction system to a range of 0.01 to 6.0, or pH 8 to 14. In order to further increase efficiency, basic conditions of pH 8 to 14 are used. It is more preferable to carry out the sol-gel reaction under

Hydrolysis and condensation to produce organic-inorganic hybrids can also be carried out in organic solvents. Examples of organic solvents that can be used in the condensation reaction include alcohols, esters, ketones, ethers, aliphatic hydrocarbon compounds, aromatic hydrocarbon compounds, amide compounds and the like.

Examples of the alcohol include, but are not limited to, monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol; ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, hexanetriol Polyhydric alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene monoethers of polyhydric alcohols such as glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; and the like.

Examples of the ester include, but are not limited to, methyl acetate, ethyl acetate, butyl acetate, γ-butyrolactone, and the like. Examples of ketones include, but are not limited to, acetone, methyl ethyl ketone, methyl isoamyl ketone, and the like.

Examples of the ether include, in addition to the above monoethers of polyhydric alcohols, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene. Polyhydric alcohol ethers obtained by alkyl-etherifying all hydroxyl groups of polyhydric alcohols such as glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether and diethylene glycol diethyl ether; tetrahydrofuran; 1,4-dioxane; anisole and the like.

Examples of the aliphatic hydrocarbon compound include, but are not limited to, hexane, heptane, octane, nonane, and decane.

Examples of the aromatic hydrocarbon compound include, but are not limited to, benzene, toluene, and xylene.

Examples of the amide compound include, but are not limited to, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like.

Among the above solvents, alcohols such as methanol, ethanol, isopropanol, butanol, etc.; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; ethers such as ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. ; and amide compounds such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferred because they are easily mixed with water. These solvents may be used alone or in combination of multiple solvents.

When compounding a filler to produce an organic-inorganic hybrid, the structure represented by RSiO _3/2 may be produced in the presence of a filler, or the structure represented by RSiO _3/2 may be compounded with a filler. You may
A condensate of a silane coupling agent may be dissolved in a commercially available dispersion filler, a filler and a silane coupling agent may be dispersed using a ball mill, a jet mill, or the like, or the alkoxysilane and the filler may undergo a condensation reaction at the same time. However, from the viewpoint of enhancing the solvent dispersibility of the filler and improving the ink jet applicability, the production method of condensing the alkoxysilane and the filler at the same time is more preferable. When the colloidal filler is treated by the sol-gel method in the presence of a silane coupling agent, the condensate of the silane coupling agent modifies the surface of the filler while filling the gaps. The pore volume can be adjusted by adjusting the amount arbitrarily. When hydroxyl groups are present on the surface of the filler, the surface hydroxyl groups and the hydroxyl groups generated by hydrolysis of the alkoxysilane interact and form ether bonds through a condensation reaction, so the compatibility between the filler and the condensate can be enhanced. , a more stable receptor can be obtained.

The surface modification of the filler with organic functional groups is carried out by surface modification while the filler is dispersed in a dispersion medium. Specifically, for example, an organic-inorganic hybrid is produced by adding the silane coupling agent to a uniform dispersion of metal oxides containing alcohol and water in the presence of a catalyst.

The organic-inorganic hybrid may be recovered by centrifuging and filtering the precipitate or gelled product, or isolated by removing the volatile solvent with an evaporator or the like.

Introduction of an organic functional group can be confirmed by FT-IR or elemental analysis. Moreover, it can be confirmed by thermogravimetric loss measurement. In order to remove the influence of adsorbed water, the thermal weight loss rate of the organic content of the inorganic filler (i) and the organic functional group (ii) combined from 150 ° C. to 1000 ° C. is 3% to 75% from the viewpoint of sensitivity. , more preferably 5% to 65% from the viewpoint of humidity resistance, and even more preferably 5% to 60% from the viewpoint of thermal stability. That is, the amount of the organic functional group in the organic-inorganic hybrid in the present embodiment is not particularly limited, but from the viewpoint of the balance between the responsiveness to the analyte and the stability of the receptor, it is preferably 75% by weight or less. Preferably, it is 65% by weight or less.

The film thickness of the receptor in the present embodiment may be a shape in which the organic-inorganic hybrid has a uniform film thickness distribution, or may have a coffee ring-like shape in which the film thickness is thickened at the ends. In the case of a coffee ring shape, the film thickness of the thinnest portion at the central portion of the receptor and the thickest portion at the end portion is preferably 10 nm or more and 50 μm or less. The film thickness is preferably 10 nm or more and 30 μm or less from the viewpoint of shortening the time required for drying during production and increasing productivity, and more preferably 10 nm or more and 20 μm or less from the viewpoint of increasing sensitivity. Further, the maximum thickness of the receptor in this embodiment is preferably 30 μm or less. The above film thickness and maximum thickness can be measured by the methods described in Examples below.

In order to use the receptor-coated surface stress sensor MSS of the present embodiment as an olfactory sensor, the organic functional groups and gas molecules interact with each other in the gas phase and diffuse into the receptor to generate stress. Preferably the gas is thereby detected.

[Surface stress type (MSS) sensor]
The sensor of this embodiment can be used as a surface stress type sensor. Preferably, the surface stress sensor is a four-point fixed piezo-element surface stress (MSS) sensor.

[Sensor manufacturing method]
The method of manufacturing the sensor of this embodiment is not particularly limited, but it can be manufactured by various methods for forming receptors on the sensor body. The receptor in the present embodiment is manufactured by, for example, dispersing an organic-inorganic hybrid in an organic solvent to prepare a coating liquid, and coating the sensor main body with the coating liquid. An inkjet device can be suitably used when applying the coating liquid onto the chip of the sensor. According to the inkjet device, droplets of a coating liquid are ejected, the droplets are coated on the sensor, and a film is formed on the receptor. FIG. 1 shows an example of forming a receptor on a chip. The sensor 1 is configured as having a chip 3 corresponding to the sensor body and a receptor 2 formed on its surface, and in the example shown in FIG. .

The method for coating the organic-inorganic hybrid on the surface of the sensor body (for example, the MSS sensor body) is not particularly limited, but for example, dip coating, spray coating, spin coating, inkjet spotting, casting, doctor blade, etc. coating methods.

Inkjet or microjet methods are preferable for coating on a 300 μmφ MSS membrane, and microjet coating is more preferable from the viewpoint of productivity.

The receptor can be produced, for example, by dispersing the organic-inorganic hybrid in an organic solvent and coating the dispersion on the MSS chip. The organic-inorganic hybrid is dispersed in an organic solvent at a concentration of 0.1 g/L to 50 g/L to form a coating liquid. From the viewpoint of productivity, the concentration is preferably 0.5 to 50 g/L, and from the viewpoint of suppressing nozzle clogging, it is more preferably 0.5 to 15 g/L.

The organic solvent for dispersing the organic-inorganic hybrid may be any solvent that can be dispersed, and preferably has a boiling point of 80°C to 250°C. A temperature of 250° C. is preferable, and a temperature of 100° C. to 200° C. is more preferable in order to shorten the drying time and improve productivity.

Examples of organic solvents include, but are not limited to, alcohol solvents, ester solvents, ketone solvents, ether solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, amide solvents, and the like.

Alcohol solvents include, but are not limited to, monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, and hexanetriol; Alcohol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol mono monoethers of polyhydric alcohols such as ethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; and the like.
Examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, γ-butyrolactone and the like.

Examples of ketone solvents include, but are not limited to, acetone, methyl ethyl ketone, methyl isoamyl ketone, and the like.

Examples of ether solvents include, but are not limited to, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, diethylene glycol dimethyl ether, Polyhydric alcohol ethers obtained by alkyl-etherifying all hydroxyl groups of polyhydric alcohols such as diethylene glycol methyl ethyl ether and diethylene glycol diethyl ether; tetrahydrofuran; 1,4-dioxane; anisole;

Examples of aliphatic hydrocarbon solvents include, but are not limited to, hexane, heptane, octane, nonane, decane, and the like.

Examples of aromatic hydrocarbon solvents include, but are not limited to, benzene, toluene, xylene, and the like.

Examples of amide solvents include, but are not limited to, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and the like.

These organic solvents may be used singly or in combination of two or more.

Among these organic solvents, N,N-dimethylformamide and propylene glycol monomethyl ether are preferred because of their excellent safety and solubility.

The receptor in this embodiment may contain additives such as arbitrary particles, ionic compounds, resins, and low-molecular-weight compounds in addition to organic-inorganic hybrids. A sensor having a receptor containing the additive can be obtained by, for example, blending the additive into a coating liquid and applying the mixture to the surface of the sensor body.

EXAMPLES The present embodiment will be specifically described below with reference to examples and comparative examples, but the present embodiment is not limited to these.

Various physical properties of the MSS olfactory sensor of each example and comparative example were evaluated according to the following (1) to (8).

(1) Molecular Weight Measurement by GPC A sample was prepared by dissolving the receptor material in DMF and passing it through a 5 μm PTFE syringe filter. GPC was measured using HLC-8420GPC manufactured by Tosoh Corporation. The analysis conditions were as follows.
<Analysis conditions>
Column TSK gel Super AWM-H × 2 flow rate 0.6 mL / min
Detector HLC-8420 GPC built-in RI detector + UV-8420
Column temperature 40°C
System temperature 40℃
Eluent 10 mM LiBr in DMF Calibration curve conditions Standard polystyrene KIT-H (manufactured by Tosoh Corporation)
Analysis used an RI detector and EcoSEC Elite-WS software was used to calculate the weight average molecular weight. The ratio of signal intensities of high weight average molecular weight and low weight average molecular weight was calculated using the signal intensity emitted by the RI detector.

(2) Identification of Organic Functional Group Species in Organic-Inorganic Hybrid Based on the following conditions, the organic functional group in the organic-inorganic hybrid was identified by measuring the receptor on the main body of the sensor by a microscopic ATR method.
(Measurement condition)
Apparatus used; Cary620 (manufactured by Agilent)
Measurement method; microscopic ATR method (crystal: Ge) using a slide-on type ATR attachment Detector; MCT (HgCeTe) infrared detection element Aperture size; about 100um
IR incident angle to ATR crystal 30°
Resolution; 4 cm ^-1
Accumulation times; 64 scans

(3) Thermal weight loss rate (quantification of the amount of organic functional groups)
A powder sample of the receptor scraped from the sensor was dried in air at 100° C., then allowed to cool to room temperature and weighed accurately. Thereafter, the organic component was removed by heating to 1000° C. at a rate of 10° C./min in the atmosphere using TGA, and the thermal weight loss rate was obtained. Since only the organic functional groups are decomposed by heating and the SiO _3/2 portion remains as silica, the thermal weight loss rate is calculated based on the amount of organic functional groups (% by mass), that is, the content of organic components in the organic-inorganic hybrid ( , expressed as “weight fraction”).

(4) Maximum thickness of the receptor By observing the uncoated part of the receptor and the maximum thickness part of the receptor in the sensor using a confocal laser microscope (VK09700 Violet Laser (manufactured by Keyence)), the thickness of the receptor was determined. was measured. That is, a cross-sectional profile between two points on the diameter of a receptor formed in a substantially circular shape was obtained, an uncoated portion and a maximum film thickness portion were specified from the cross-sectional profile, and the difference between them was taken as the maximum thickness.
(Observation conditions)
Objective lens: Standard lens, 20.0x Measurement area: Plane Measurement mode: Surface shape RPD: Accuracy priority Measurement quality: High definition Measurement pitch: 0.5 μm
Z measurement distance: 37.92 μm
Wide dynamic range: OFF
Brightness 1:648
Neutral filter: 100%
Optical zoom: 1x Average count: 1 Filter: OFF
White balance mode: One push White balance R: 131
White balance B: 138
Received light amount correction mode: γ correction γ correction value: 0.45
γ offset: 0
Black and white inversion: OFF
Head type: VK-9700
Light intensity eccentricity correction: ON
Field curvature correction: ON
XY calibration: 688 nm/pixel
Z calibration: 1 nm/digit
Vividness: 5
Contrast: 5
Brightness: 0

(5) Influence of Humidity Resistance 100 ppm of gaseous ethanol was used as an analyte. Under dry conditions at 25° C., 100 ppm of ethanol was purged with nitrogen for 10 minutes, this was repeated three times, and the signal intensity was measured.
Similarly, under conditions of 25° C. and 30 RT %, 100 ppm of ethanol was purged with nitrogen for 10 minutes, and this was repeated three times to measure the signal intensity.
Then, 100 × ("Intensity of the third signal measured under dryness" - "Intensity of the third signal measured under 30 RT%") / ("Intensity of the third signal measured under dryness""Strength" is the attenuation rate (%), S if the value is 20% or less, A if 21% to 40% or less, B if 41% or more and less than 50%, C if 51% or more and

(6) Physical and chemical stability (first time)
Water-saturated steam was used as the analyte. Signal intensity was measured at 25° C. under dry conditions with a 10 minute purge of water-saturated steam with 6 sccm nitrogen (total flow set at 30 sccm).
(Second time)
Ethanol was used as the analyte. Signal intensity was measured at 25° C. under dry conditions with a headspace gas of ethanol purged with 6 sccm nitrogen for 10 minutes (total flow set at 30 sccm).
(3rd time)
Toluene was used as the analyte. Signal intensity was measured at 25° C. under dry conditions with a headspace gas of toluene purged with 6 sccm of nitrogen for 10 minutes (total flow set at 30 sccm).
After each measurement, changes in the film shape were observed with an optical microscope and evaluated as follows.
A: No change was observed even after the third time.
B . . . No change was observed after the second time, but a clear change in the shape of the film was observed after the third time under a microscope with a magnification of 200 times.

C: A clear change in the shape of the film after the second time was observed under a microscope with a magnification of 200 times.

(7) Heat resistance (reflow resistance)
After reflowing at 250° C. for 30 seconds, C was given when peeling, deformation, cracks, etc. were observed in the receiver, and A was given when no such peeling was observed.

(8) Filler particle size (diameter)
The number average value of 50 filler particles was obtained using the scanning electron microscope described in (1) above. In the case of spherical particles, the maximum diameter was defined as the particle diameter, and in the case of chain-shaped particles, the chain width was defined as the particle diameter, and the number average value for 50 particles was calculated.

<Example 1>
In a separable flask, 27.1 g of phenyltrimethoxysilane was added to 50 g of chain colloidal silica 2-propanol dispersion IPA-ST-UP (Nissan Kagaku), 90 g of water, 10 g of 28% aqueous ammonia, and 300 g of 2-propanol. The reaction was carried out at 80°C for 4 hours. After air-cooling the reaction solution, the precipitate was isolated by centrifuging at 6000 rpm for 10 minutes. After thoroughly washing the sample with ethanol, it was dissolved in N,N dimethylformamide to a concentration of 10 mg/mL to obtain a coating solution. A portion of the sample was dried at 80° C. under vacuum and the thermal weight loss rate was measured. A surface stress sensor with a sensitive film was obtained by applying 30 droplets of the coating liquid in an amount of 300 pL per droplet onto the MSS surface placed on a hot plate at 80° C. using an inkjet device. Its appearance was the same as that shown in FIG.

FIG. 2 shows the results of GPC. The high weight average molecular weight was 176,000, the low weight average molecular weight was 1,600, and the high weight average molecular weight signal intensity was 0.93%.
Moreover, as a result of measuring the maximum thickness of the surface stress sensor according to Example 1 based on the method (4) above, the image shown in the upper part of FIG. 3 was obtained. From the image at the top of FIG. 3, it can be seen that a coffee-ring-shaped receptor is formed on a sensor body of 700 μm long×500 μm wide.
Furthermore, as a result of analyzing the film thickness, the film thickness distribution shown in the lower part of FIG. 4 was obtained. The image at the bottom of FIG. 3 shows a cross-sectional profile between two points in the XX' cross section at the top of FIG. A maximum thickness was obtained. Results are shown in Table 1.
Furthermore, FIG. 4 shows the result of examining the effect of humidity resistance based on the method (5) above. A maximum amplitude of 550 μV was obtained at a humidity of 0% (dry) and a maximum amplitude of 360 μV was obtained at a humidity of 30%. Since the attenuation rate calculated by the method described above was 40%, ◯ was given.
The following examples and comparative examples were also evaluated in the same manner as the method described above.

<Example 2>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 13.5 g. FIG. 5 shows the results of GPC. The high weight average molecular weight was 444,000, the low weight average molecular weight was 1,500, and the high weight average molecular weight signal intensity was 19%.

<Example 3>
Example 1 was followed except that 50 g of IPA-ST-UP (Nissan Kagaku) was changed to 25 g of IPA-ST (12 nm spherical silica).

<Example 4>
Example 1 was followed except that 50 g of IPA-ST-UP (Nissan Kagaku) was changed to 25 g of IPA-ST-L (45 nm spherical silica).

<Example 5>
Example 1 was followed except that 50 g of IPA-ST-UP (Nissan Kagaku) was changed to 20 g of MP-4540M (450 nm spherical silica).

<Example 6>
Example 1 was followed except that 50 g of IPA-ST-UP (product of Nissan Chemical Industries) was changed to 20 g of ZR-40BL (90 nm zirconia).

<Example 7>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 37.6 g of 4-chlorophenyltriethoxysilane.

<Example 8>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 30.4 g of 4-methoxyphenyltrimethoxysilane.

<Example 9>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 31.5 g of 3-furyltriethoxysilane.

<Example 10>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 33.9 g of 3-thienyltriethoxysilane.

<Example 11>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 23.3 g of 4-aminophenyltrimethoxysilane.

<Example 12>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was replaced with 29 g of p-tolyltrimethoxysilane.

<Example 13>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.2 g of naphthalenetrimethoxysilane.

<Example 14>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+37.5 g of 3-(2-imizazolinepropyl)triethoxysilane.

<Example 15>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+36.1 g of 3-(2-aminopropylethylamino)propyltriethoxysilane.

<Example 16>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+35.7 g of norbornyltriethoxysilane.

<Example 17>
Example 1 was repeated except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+7.08 g of 3-N,N-dimethylaminopropyltrimethoxysilane.

<Example 18>
Example 1 was repeated except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+9.77 g of 3-mercaptopropyltriethoxysilane.

<Example 19>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 24.4 g of phenyltrimethoxysilane+3.93 g of pentafluorophenyltrimethoxysilane.

<Example 20>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+11.9 g of 3-methacryloxypropyltriethoxysilane.

<Example 21>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+8.75 g of 2-(3,4-epoxycyclohexyltrimethoxysilane.

<Example 22>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane and 8.74 g of 4-aminophenyltrimethoxysilane.

<Example 23>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+21.6 g of 3-ureidopropyltriethoxysilane.

<Example 24>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+10.4 g of 3-phenylaminopropyltrimethoxysilane.

<Example 25>
Example 1 was followed except that 27.1 g of phenyltrimethoxysilane was changed to 27.1 g of phenyltrimethoxysilane+25.3 g of 3-[bis[(diphenylphosphino)methyl]amino]propyltrimethoxysilane.

<Example 26>
18 g of water, 2 g of 28% aqueous ammonia, 80 g of 2-propanol, and 6 g of phenyltrimethoxysilane were added to a 500 mL separable flask and reacted at 80° C. for 4 hours. After air-cooling the reaction solution, the precipitate was isolated by centrifuging at 6000 rpm for 10 minutes. After thoroughly washing the sample with ethanol and drying it, it was dissolved in N,N dimethylformamide to a concentration of 10 g/mL. A 2-propanol dispersion of linear colloidal silica IPA-ST-UP (Nissan Kagaku) was adjusted to 10 mg/mL with N,N dimethylformamide, and the above solution was mixed at a ratio of 5:5. A coating liquid was obtained. A portion of the sample was dried at 80° C. under vacuum and the thermal weight loss rate was measured. 30 droplets of the coating liquid were applied onto the surface of the MSS placed on a hot plate at 40° C. using an inkjet device in an amount of 300 pL per droplet.

<Example 27>
30 g of ethanol, 4.7 g of tetraethoxysilane, 4.3 g of phenyltriethoxysilane, and 1.8 g of 28% aqueous ammonia were mixed in a 500 mL separable flask, stirred, and allowed to stand at room temperature until gelation. The resulting gel was washed with ethanol to remove ammonia, and then dissolved in DMF to a concentration of 10 mg/mL to obtain a coating solution. The coating solution was applied onto the MSS surface placed on a hot plate at 80° C. with 30 drops at a volume of 300 pL per drop using a microjet.

<Example 28>
In a 500 mL separable flask, 37 g of ethanol, 2.6 g of tetraethoxysilane, 9.0 g of phenyltriethoxysilane, and 2.26 g of 28% aqueous ammonia were mixed, stirred, and allowed to stand at room temperature until gelation. The resulting gel was washed with ethanol to remove ammonia, and then dissolved in DMF to a concentration of 10 mg/mL to obtain a coating solution. The coating solution was applied onto the MSS surface placed on a hot plate at 80° C. with 30 drops at a volume of 300 pL per drop using a microjet.

<Example 29>
Example 9 was followed except that 10.1 g of 3-furyltriethoxysilane was used.

<Example 30>
Example 9 was followed except that 17.3 g of 3-furyltriethoxysilane was used.

<Example 31>
A surface stress sensor with a receptor was obtained by applying 150 droplets of the coating liquid of Example 1 in an amount of 700 pL per droplet to the MSS surface placed on a hot plate at 80°C using an inkjet device. rice field.
<Example 32>
Example 26 was followed except that the ratio of Example 26 was changed from 5:5 to 1:9.

<Comparative Example 1>
Silica-titania particles (granular) were synthesized according to the method described in WO2016/121155. It was synthesized by cohydrolysis and condensation polymerization reaction of aminopropyltrimethoxysilane and titanium tetraisopropoxide (TTIP) in an ammonia basic isopropanol (IPA) aqueous solution in which octadecylamine (ODA) was dissolved. The above synthesis reaction was carried out using a Teflon (registered trademark) microreactor having a micrometer-sized Y-shaped channel. The four precursor solutions are solution 1: aminopropyltrimethoxysilane/IPA, solution 2: H ₂ O/IPA/ammonia, solution 3: TTIP/IPA, and solution 4: H ₂ O/IPA. The volume was adjusted up to 4 and prepared. The precursor solution was simultaneously fed at a constant speed by a syringe pump. Solutions 1 and 2, and solutions 3 and 4 were mixed in parallel microreactors, respectively, and the discharged liquids from both reactors were further mixed in another microreactor to form one reaction liquid. The reaction liquid was discharged into a separately prepared precursor solution 5: ODA/H2O/IPA, and stirred at a constant speed until the discharge was completed. After that, it was allowed to stand at room temperature to obtain a nanoparticle (NH ₂ —STNP) dispersion. Since such nanoparticles were confirmed to have a structure represented by RSiO _3/2 , they were treated as organic-inorganic hybrids. After air-cooling the reaction solution, the precipitate was isolated by centrifuging at 6000 rpm for 10 minutes. After thoroughly washing the sample with ethanol, it was dissolved in N,N-dimethylformamide to a concentration of 1 g/mL to obtain a coating solution. A surface stress sensor with a receptor was obtained by applying 300 droplets of the coating solution in an amount of 300 pL per droplet onto the MSS surface placed on a hot plate at 80° C. using a microjet.

<Comparative Example 2>
Comparative Example 1 was followed except that a nanoparticle (C ₁₈ -STNP) dispersion obtained by using octadecyltriethoxysilane instead of aminopropyltrimethoxysilane was used. Since the structure represented by RSiO _3/2 was confirmed in the above nanoparticles, they were treated as an organic-inorganic hybrid.

<Comparative Example 3>
Comparative Example 1 was followed except that a nanoparticle (phenyl-STNP) dispersion obtained by using phenyltrimethoxysilane instead of aminopropyltrimethoxysilane was used. Since the structure represented by RSiO _3/2 was confirmed in the above nanoparticles, they were treated as an organic-inorganic hybrid. Similar to Example 1, FIG. 6 shows the result of confirming the response signal to 100 ppm ethanol at 0% and 30% humidity. Comparative Example 1 showed significant signal attenuation with 30% humidity.

<Comparative Example 4>
Poly(methyl methacrylate) (Aldrich, average Mw ~15,000 by GPC, powder) was diluted with N,N-dimethylformamide to 1 g/mL to prepare a coating solution. 300 droplets of the coating solution were applied onto the MSS surface placed on a hot plate at 80° C. using a microjet at a volume of 300 pL per droplet. No signal was observed at 100 ppm of ethylene, and 500 ppm of ethylene, ethanol, acetaldehyde, and toluene were measured at 25°C three times each for 10 minutes/purge for 10 minutes. bottom.

<Comparative Example 5>
A chain colloidal silica 2-propanol dispersion IPA-ST-UP (Nissan Kagaku Co., Ltd.) was diluted with DMF to 10 mg/mL, and 350 drops were applied at an amount of 300 pL per drop using an inkjet device. A surface stress sensor with a receptor was obtained by coating it on the MSS surface placed on a hot plate at 80°C.

<Comparative Example 6>
A chain colloidal silica 2-propanol dispersion IPA-ST-UP (Nissan Kagaku Co., Ltd.) was diluted with DMF to 10 mg/mL, and an inkjet device was used to apply 30 drops in an amount of 300 pL per drop. A surface stress sensor with a sensitive film was obtained by coating the MSS surface placed on a hot plate at 80°C.

<Comparative Example 7>
10 g of phenyltrimethoxysilane, 10 g of water, 30 g of ethanol and 28% aqueous ammonia were mixed and reacted at 80° C. for 2 hours. The precipitate was isolated by centrifugation at 6000 rpm for 10 minutes. After thoroughly washing the sample with ethanol, it was dissolved in N,N-dimethylformamide to a concentration of 1 g/mL to obtain a coating solution. The coating solution was applied onto the MSS surface placed on a hot plate at 80° C. with 300 drops at a volume of 300 pL per drop using a microjet.

FIG. 8 shows the results of identification of the organic functional groups in the receptors on the sensor bodies in Example 1 and Comparative Example 5 by the method (2) above. A signal originating from the introduced phenyl group was detected. Also, in Example 1, a structure represented by RSiO _3/2 was observed, whereas in Comparative Example 5, such a structure was not observed. Organic functional group species were similarly identified for other examples and comparative examples.

The results of the above measurements (1) to (8) for each example/comparative example are shown in Tables 1 to 3 below.

INDUSTRIAL APPLICABILITY The sensor of the present invention has the effect of exhibiting a response with high sensitivity to hydrophilic gases such as ethanol and acetaldehyde even in the presence of humidity.

1 sensor 2 receptor 3 chip (sensor body)

Claims (12)

A sensor having a receptor layer comprising an organic-inorganic hybrid,
The receptor layer has a structure containing units represented by the formula RSiO _3/2 (wherein R represents an organic functional group),
The organic-inorganic hybrid includes a first component having a weight average molecular weight of 800 to 10000 and a second component having a weight average molecular weight of 30000 to 2000000,
The sensor, wherein the peak area of the second component measured by GPC is 0.01% to 55% of the total peak area of the first component and the second component. 2. The sensor of claim 1, wherein said second component is a filler. 3. The sensor of Claim 2, wherein the filler comprises a metal oxide. 4. The sensor of any one of claims 2 or 3, wherein the filler comprises silica. 5. The sensor according to any one of claims 2 to 4, wherein the shape of said filler is spherical or chain-like. 6. The sensor of any one of claims 1-5, wherein the organic functional group comprises at least one or more aromatic ring structures. 7. The sensor of claim 6, wherein said aromatic ring structure of said organic functional group is directly attached to a Si atom. 8. The sensor according to claim 6, wherein the organic functional group is a copolymer structure of an aromatic ring structure and a non-aromatic ring structure. 9. The sensor according to claim 8, wherein the non-aromatic ring structure comprises one selected from the group consisting of nitrogen atoms, oxygen atoms, sulfur atoms, halogen atoms, boron atoms and phosphorus atoms. 10. The sensor according to any one of claims 1 to 9, wherein the content of the organic component in the organic-inorganic hybrid is 75% by weight or less. 11. A sensor according to any one of claims 1 to 10, wherein the maximum thickness of the receptor layer is 30 [mu]m or less. 12. A sensor according to any preceding claim, wherein the sensor is a surface stress sensor.

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