JP2021089152A - Enzyme sensor electrode forming composition, enzyme sensor electrode, and enzyme sensor - Google Patents

Abstract

To provide a composition for forming an enzyme sensor electrode, an enzyme sensor electrode, and an enzyme sensor having excellent sensitivity and adhesion.SOLUTION: The above problems can be solved by an enzyme sensor electrode forming composition containing a conductive material and/or an oxidoreductase, aqueous resin fine particles, and an aqueous liquid medium. Further, the above problems can be solved by the enzyme sensor electrode forming composition including the aqueous resin fine particles containing an acrylic emulsion polymer or a methacrylic emulsion polymer.SELECTED DRAWING: None

Description

The present invention relates to an enzyme sensor electrode forming composition, an enzyme sensor electrode, and an enzyme sensor.

Enzyme sensors that easily measure specific components contained in biological samples such as blood and sweat and foods have been put into practical use. For example, a blood glucose level sensor that detects or quantifies glucose in blood by an electrochemical means can be mentioned. This is to selectively oxidize glucose contained in blood by the substrate specificity of the enzyme, and the electric charge reaches the electrode through the mediator or directly to generate an electric current, and the glucose concentration is quantified from the electric current value. Can be done.
As the electrode portion of the enzyme sensor that has been put into practical use, one in which a metal layer is formed by sputtering, plating, or the like may be used (for example, Patent Document 1). However, the measurement sensitivity is still not sufficient, and it is preferable not to use an expensive metal from the viewpoint of corrosion and cost. Further, since it is desired that the electrode is used without the constituents peeling off, the binder that binds the electrode member is required to have strong adhesion, but it is desirable that the total amount of resin is small.

Japanese Unexamined Patent Publication No. 2008-045877

An object of the present invention is to provide an enzyme sensor electrode forming composition, an enzyme sensor electric electrode, and an enzyme sensor having excellent sensitivity and adhesion.

The present inventors have reached the present invention as a result of repeated studies for solving the above-mentioned problems.
That is, the present invention relates to an enzyme sensor electrode forming composition containing a conductive material and / or an oxidoreductase, aqueous resin fine particles, and an aqueous liquid medium.

The present invention also relates to the composition for forming an enzyme sensor electrode, wherein the aqueous resin fine particles contain an acrylic emulsion and / or a methacrylic emulsion.

The present invention also relates to the composition for forming an enzyme sensor electrode, wherein the aqueous resin fine particles contain crosslinked resin fine particles.

The present invention also relates to the enzyme sensor electrode forming composition in which the conductive material is a carbon material.

The present invention further relates to the enzyme sensor electrode forming composition containing a water-soluble dispersant.

The present invention also relates to an enzyme sensor electrode formed from the enzyme sensor electrode forming composition.

The present invention further relates to the enzyme sensor electrode containing one or more kinds of oxidoreductases.

The present invention also relates to the enzyme sensor electrode forming composition or an enzyme sensor including the enzyme sensor electrode.

The present invention also relates to an enzyme sensor in which the substance to be sensed is selected from glucose, fructose, and lactic acid.

According to the present invention, the composition for forming an enzyme sensor electrode in which aqueous resin fine particles are dispersed together with a conductive material and / or an oxidoreductase has excellent adhesion between particles and with a base material when a coating film is formed. A high-strength enzyme sensor electrode can be provided.

Further, since the binding of the aqueous resin fine particles with the conductive material and / or the oxygen reductase is by point contact, it is difficult to inhibit the distribution of the enzyme in the electrode, for example. When a mediator that transfers electrons between the enzyme and the electrode is used, it is excellent in diffusion in the electrode. Further, since the adhesiveness is excellent, a small amount of resin is required, and as a result, the resistance due to the resin can be reduced. That is, by using a composition for forming an enzyme sensor electrode containing a conductive material and / or an oxygen reduction catalyst and aqueous resin fine particles, an enzyme sensor having excellent sensitivity can be provided.

<Composition for forming electrodes for enzyme sensors>
The enzyme sensor electrode forming composition of the present invention (hereinafter, also referred to as a mixture ink) contains at least a conductive material and / or an oxygen reductase, an aqueous resin fine particle (A), and an aqueous liquid medium. .. The proportions of the conductive material and / or the oxygen reduction catalyst, the aqueous resin fine particles, and the aqueous liquid medium are not particularly limited and may be appropriately selected within a wide range.

<Conductive material>
Next, the conductive material will be described. The conductive material is contained to enhance the electron conductivity at the electrode and facilitate the redox reaction. Here, carbon materials are mainly mentioned, but the present invention is not limited to this.
The carbon material which is the conductive material used in the present invention is not particularly limited as long as it is a conductive carbon material, but carbon black, graphite, and conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers). ), Graphene, fullerene, etc. can be used alone or in combination of two or more.

Carbon black includes furnace black, which is produced by continuously pyrolyzing a gas or liquid raw material in a reactor, especially acetylene black, which is made from ethylene heavy oil, and the raw material gas is burned to burn the flame to the bottom of the channel steel. Various types such as channel black that has been rapidly cooled and precipitated, thermal black that is obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, and acetylene black that uses acetylene gas as a raw material, alone or 2 More than one type can be used together. In addition, normally oxidized carbon black, hollow carbon, and the like can also be used.

As the specific surface area of the carbon black used increases, the contact points between the carbon black particles increase, which is advantageous for lowering the internal resistance of the electrode and increases the amount of the enzyme supported on the carbon surface, which is effective. Is. Specifically, the specific surface area (BET) obtained from the amount of nitrogen adsorbed is 20 m ² / g or more and 1500 m ² / g or less, preferably 50 m ² / g or more and 1500 m ² / g or less, and ^{more preferably 100 m 2.} It is desirable to use the one of / g or more and 1500 m ^{2 / g or less.}

The particle size of the carbon black used is preferably 0.005 to 1 μm in terms of primary particle size, and particularly preferably 0.01 to 0.2 μm. However, the primary particle size referred to here is an average of the particle sizes measured by an electron microscope or the like.

It is desirable that the dispersed particle size of the carbon material, which is a conductive material, in the mixed ink is miniaturized to 0.03 μm or more and 5 μm or less.

The dispersed particle size here is a particle size (D50) that becomes 50% when the volume ratio of the particles is integrated from the fine particle size distribution in the volume particle size distribution, and is generally used. It is measured with a particle size distribution meter, for example, a dynamic light scattering type particle size distribution meter (“Microtrack UPA” manufactured by Nikkiso Co., Ltd.).

Examples of commercially available carbon black include Talker Black # 4300, # 4400, # 4500, # 5500 (Tokai Carbon Co., Ltd., Furness Black), Graphite L etc. (Degsa Co., Ltd., Furness Black), Raven7000, 5750, etc. 5250, 5000 ULTRAIII, 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc., PUER BLACK100, 115, 205, etc. (Columbian, Furness Black), # 2350, # 2400B, # 2600B, # 30050B, # 3030B # 3350B, # 3400B, # 5400B, etc. (manufactured by Mitsubishi Chemical Co., Ltd., Furness Black), MONARCH1400, 1300, 900, VulcanXC-72R, BlackPearls2000, etc. (manufactured by Cabot Co., Ltd., Furness Black), Ensaco250G, Ensaco260G, Ensaco350G, Super As graphite, for example, TIMCAL), Ketjen Black EC-300J, EC-600JD (Akzo), Denka Black, Denka Black HS-100, FX-35 (Electrochemical Industry Co., Ltd., acetylene black), etc. Natural graphite such as artificial graphite, flake graphite, lump graphite, and earth graphite can be mentioned, but the present invention is not limited to these, and two or more types may be used in combination.

As the conductive carbon fiber, those obtained by firing from a raw material derived from petroleum are preferable, but those obtained by firing from a raw material derived from a plant can also be used. For example, VGCF manufactured by Showa Denko KK, which is manufactured from petroleum-derived raw materials, can be mentioned.

<Oxidoreductase>
The enzyme in the present invention is not particularly limited as long as it is an enzyme capable of transferring electrons by reaction, and is appropriately selected depending on the detection target.
For example, oxidases such as sugars and organic acids and dehydrogenases can be used. Among them, glucose oxidase and glucose dehydrogenase, which can detect glucose contained in a biological sample such as human blood or urine, may be preferable. In addition, fructose oxidase or fructose dehydrogenase capable of detecting fructose, or lactate oxidase or lactate dehydrogenase capable of detecting lactic acid may be preferable.
The enzyme used may be one type or two or more types. Further, it may be a combination of a catalyst such as an enzyme that brings the sensing target into a state in which it can be oxidized or reduced by hydrolysis or the like, and an enzyme that promotes oxidation or reduction.

<Mediator>
Enzymes include direct electron transfer type (DET type) enzymes that can directly transfer electrons to electrodes and enzymes that cannot directly transfer electrons. In the case of a non-DET type enzyme, it is necessary to use a mediator that plays a role of transferring electrons generated by oxidation of the sensing target from the enzyme to the electrode. The mediator is not particularly limited as long as it is a redox substance capable of transmitting electrons to the electrode, and conventionally known mediators can be used. As a method of using the mediator, there are a method of supporting it on an electrode, a method of dissolving it in an electrolytic solution, and the like. Examples of the mediator include non-metal compounds such as tetrathiafluvalene, hydroquinone and quinones such as 1,4-naphthoquinone, ferrocene, ferricianides, osmium complexes, and polymers modified with these compounds.

<Aqueous resin fine particles>
The aqueous resin fine particles are those in which the resin does not dissolve in water and exists in the state of fine particles, and the aqueous dispersion is generally also called an aqueous emulsion and can be used in the present invention.
Examples of the emulsion used include (meth) acrylic emulsion, nitrile emulsion, urethane emulsion, diene emulsion (SBR, etc.), fluorine emulsion (PVDF, PTFE, etc.) and the like. Unlike the water-soluble polymer, the emulsion preferably has excellent bondability and flexibility (film flexibility) between particles.
(Particle structure of water-based resin fine particles)
Further, the particle structure of the aqueous resin fine particles used in the present invention may be a multilayer structure, so-called core-shell particles. For example, by localizing a resin in which a monomer having a functional group is mainly polymerized in the core portion or the shell portion, or by providing a difference in Tg and composition between the core and the shell, curability and drying are performed. It is possible to improve the property, film forming property, and mechanical strength of the binder.

(Particle size of water-based resin fine particles)
The average particle size of the aqueous resin fine particles used in the present invention is preferably 10 to 500 nm, more preferably 10 to 300 nm, from the viewpoint of binding properties and particle stability. Further, if a large amount of coarse particles exceeding 1 μm is contained, the stability of the particles is impaired, so that the amount of coarse particles exceeding 1 μm is preferably 5% or less at most. The average particle size in the present invention represents the volume average particle size and can be measured by a dynamic light scattering method.

The average particle size can be measured by the dynamic light scattering method as follows. The aqueous resin fine particle dispersion is diluted 200 to 1000 times with water depending on the solid content. Approximately 5 ml of the diluted solution is injected into a cell of a measuring device [Microtrac manufactured by Nikkiso Co., Ltd.], and the measurement is performed after inputting the refractive index conditions of the solvent (water in the present invention) and the resin according to the sample. The peak of the volumetric particle size distribution data (histogram) obtained at this time is taken as the average particle size of the present invention.

<(Meta) acrylic emulsion>
Next, the (meth) acrylic emulsion will be described. The (meth) acrylic emulsion is an emulsion polymer containing 10 parts by mass or more of a monomer having a (meth) acryloyl group, preferably 20 parts by mass or more, and more preferably 30 parts by mass or more. It is good. Since the monomer having a (meth) acryloyl group has excellent reactivity, resin fine particles can be produced relatively easily. Further, the coating film made of the (meth) acrylic emulsion is excellent in adhesion and flexibility.

When a (meth) acrylic emulsion is used, it is preferable to contain crosslinked resin fine particles described below. The crosslinked resin fine particles indicate resin fine particles having an internal crosslinked structure (three-dimensional crosslinked structure), and it is important that the particles are crosslinked inside the particles. The cross-linked resin fine particles have a cross-linked structure, so that the electrolytic solution elution resistance can be ensured, and the effect can be enhanced by adjusting the cross-linking inside the particles. Further, when the crosslinked resin fine particles contain a specific functional group, it is possible to contribute to the adhesion to the base material or other electrode constituent materials. Furthermore, by adjusting the crosslinked structure and the amount of functional groups, it is possible to obtain a mixture ink having excellent durability of the enzyme sensor.
In addition, cross-linking between particles (cross-linking between particles) can be used in combination for cross-linking, but in this case, since a cross-linking agent is added later, the cross-linking agent component leaks into the electrolytic solution or when the electrode is manufactured. There may be variations. Therefore, it is necessary to use the cross-linking agent to the extent that the electrolytic solution resistance is not impaired.

The crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention are obtained by emulsion polymerization of an ethylenically unsaturated monomer in water with a radical polymerization initiator in the presence of a surfactant. It is a resin fine particle to be obtained. The (meth) acrylic emulsion preferably used in the present invention is preferably obtained by emulsion polymerization of an ethylenically unsaturated monomer containing the following monomers (C1) and (C2) in the following proportions.
(C1) From the group consisting of an ethylenically unsaturated monomer (c1) having a monofunctional or polyfunctional alkoxysilyl group and a monomer (c2) having two or more ethylenically unsaturated groups in one molecule. At least one monomer selected: 0.1-5% by weight
(C2) Ethylene unsaturated monomer (c3) other than the monomers (c1) to (c2): 95 to 99.9% by mass.
(However, the total of the above (c1) to (c3) is 100% by mass)

Of the ethylenically unsaturated monomers constituting the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention, (c1) and (c3) are contained in one molecule unless otherwise specified. It indicates a monomer having one ethylenically unsaturated group.

<About the monomer group (C1)>
The functional groups (alkoxysilyl group, ethylenically unsaturated group) of the monomer contained in the monomer group (C1) are self-crosslinking reactive functional groups, which mainly perform internal cross-linking during particle synthesis. Has the effect of forming. Sufficient internal cross-linking of particles can improve the electrolytic solution resistance. Therefore, crosslinked resin fine particles can be obtained by using the monomer contained in the monomer group (C1). In addition, the electrolytic solution resistance can be improved by sufficiently performing particle cross-linking.

Examples of the monomer (c1) having one ethylenically unsaturated group and an alkoxysilyl group in one molecule include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, and γ-. Methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyl Examples thereof include dimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, and vinylmethyldimethoxysilane.

Examples of the monomer (c2) having two or more ethylenically unsaturated groups in one molecule include allyl (meth) acrylate, 1-methylallyl (meth) acrylate, and 2-methylallyl (meth) acrylate. , (Meta) acrylate 1-butenyl, (meth) acrylate 2-butenyl, (meth) acrylate 3-butenyl, (meth) acrylate 1,3-methyl-3-butenyl, (meth) acrylate 2- Chlorallyl, 3-chloroallyl (meth) acrylate, o-allylphenyl (meth) acrylate, 2- (allyloxy) ethyl (meth) acrylate, allyllactyl (meth) acrylate, citronellyl (meth) acrylate, (meth) Geranyl acrylate, Loginyl (meth) acrylate, Synamyl (meth) acrylate, diallyl maleate, diallyl itaconic acid, vinyl (meth) vinyl acrylate, vinyl crotonate, vinyl oleate, vinyl linolenate, (meth) acrylic acid (Meta) acrylic acid esters containing ethylenically unsaturated groups such as 2- (2'-vinyloxyethoxy) ethyl; ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, di (meth) Tetraethylene glycol acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-trishydroxymethylethane diacrylic acid, 1,1,1-trishydroxymethyl triacrylate Polyfunctional (meth) acrylic acid esters such as ethane, 1,1,1-trishydroxymethylpropantriacrylic acid; divinyls such as divinylbenzene and divinyl adipate; diallyl isophthalate, diallyl phthalate, diallyl maleate, etc. Diaryls and the like can be mentioned.

The alkoxysilyl group or ethylenically unsaturated group in the monomer (c1) or the monomer (c2) is mainly intended to self-condensate or polymerize during polymerization to introduce a crosslinked structure into the particles. However, a part of it may remain inside or on the surface of the particles even after polymerization. The remaining alkoxysilyl group or ethylenically unsaturated group contributes to the interparticle cross-linking of the binder composition. In particular, the alkoxysilyl group is preferable because it has an effect of contributing to the improvement of adhesion to the substrate.

In the present invention, the monomer contained in the monomer group (C1) is used in an amount of 0.1 to 5% by mass in the entire ethylenically unsaturated monomer (total 100% by mass) used for emulsion polymerization. It is characterized by that. It is preferably 0.5 to 3% by mass.

<About the monomer group (C2)>
The crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention include the above-mentioned monomer (c1) having one ethylenically unsaturated group and an alkoxysilyl group in one molecule. In addition to the monomer (c2) having two or more ethylenically unsaturated groups in one molecule, the monomer group (C2) is ethylenically other than the monomers (c1) and (c2). It can be obtained by simultaneously emulsifying and polymerizing a monomer (c3) having an unsaturated group.

The monomer (c3) is not particularly limited as long as it is a monomer other than the monomers (c1) and (c2) and has an ethylenically unsaturated group.
Monomer (c4) having one ethylenically unsaturated group in one molecule and a monofunctional or polyfunctional epoxy group, one ethylenically unsaturated group in one molecule, and a monofunctional or polyfunctional amide group At least one monomer selected from the group consisting of a monomer (c5) having and, and a monomer (c6) having one ethylenically unsaturated group in one molecule and a monofunctional or polyfunctional hydroxyl group. The body and the monomer (c7) having an ethylenically unsaturated group other than the monomers (c1), (c2), (c4) to (c6) can be used.
By using the monomers (c4) to (c6), an epoxy group, an amide group, or a hydroxyl group can be left in the particles or on the surface of the crosslinked resin fine particles, whereby the adhesion of the base material and the like can be maintained. Physical properties can be improved. The functional groups of the monomers (c4) to (c6) are likely to remain inside or on the surface of the particles even after particle synthesis, and even a small amount has a large adhesion effect to the substrate. In addition, a part of it may be used for a crosslinking reaction, and by adjusting the degree of crosslinking of these functional groups, it is possible to balance the electrolyte resistance and the adhesion.

Examples of the monomer (c4) having one ethylenically unsaturated group and a monofunctional or polyfunctional epoxy group in one molecule include glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate. And so on.

Examples of the monomer (c5) having one ethylenically unsaturated group and a monofunctional or polyfunctional amide group in one molecule include a primary amide group-containing ethylenically unsaturated mono such as (meth) acrylamide. Meters: Alkyrol (meth) acrylamides such as N-methylolacrylamide, N, N-di (methylol) acrylamide, N-methylol-N-methoxymethyl (meth) acrylamide; N-methoxymethyl- (meth) acrylamide, Monoalkoxy (meth) acrylamides such as N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl- (meth) acrylamide; N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethyl metaacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethyl metaacrylamide, N, N- Di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) metaacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) metaacrylamide, N, N- Dialkoxy (meth) acrylamides such as di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) metaacrylamide; N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, etc. Dialkylamino (meth) acrylamides; dialkyl (meth) acrylamides such as N, N-dimethylacrylamide, N, N-diethylacrylamide; keto group-containing (meth) acrylamides such as diacetone (meth) acrylamide. ..

Examples of the monomer (c6) having one ethylenically unsaturated group and a monofunctional or polyfunctional hydroxyl group in one molecule include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. , 4-Hydroxybutyl (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, allyl Examples include alcohol.

Some of the functional groups of the monomers contained in the monomers (c4) to (c6) may react during particle polymerization and be used for intraparticle cross-linking. In the present invention, the monomers contained in the monomers (c4) to (c6) are 0.1 to 20% by mass in the entire ethylenically unsaturated monomer (100% by mass in total) used for emulsion polymerization. It is characterized by being used. It is preferably 1 to 15% by mass, and particularly preferably 2 to 10% by mass.

The monomer (c7) is not particularly limited as long as it is a monomer other than the monomers (c1), (c2), (c4) to (c6) and has an ethylenically unsaturated group. For example, a monomer (c8) having one ethylenically unsaturated group in one molecule and an alkyl group having 8 to 18 carbon atoms, one ethylenically unsaturated group in one molecule, and a cyclic structure. Examples thereof include the monomer (c9) having. When the monomer (c8) and / or the monomer (c9) is used for emulsion polymerization as the monomer (c7), the monomer (c7) contains other monomers. (May be said), the entire monomer (c1), (c2), (c4) to (c6) and (c7) in which the monomers (c8) and (c9) have an ethylenically unsaturated group). It is preferably contained in a total of 30 to 95% by mass. It is preferable to use the monomer (c8) or the monomer (c9) because it is excellent in particle stability and electrolytic solution resistance during particle synthesis.

Examples of the monomer (c8) having one ethylenically unsaturated group and an alkyl group having 8 to 18 carbon atoms in one molecule include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and myristyl. Examples thereof include (meth) acrylate, cetyl (meth) acrylate, and stearyl (meth) acrylate.

Examples of the monomer (c9) having one ethylenically unsaturated group in one molecule and a cyclic structure include an alicyclic ethylenically unsaturated monomer and an aromatic ethylenically unsaturated monomer. Be done. Examples of the alicyclic ethylenically unsaturated monomer include cyclohexyl (meth) acrylate and isovonyl (meth) acrylate, and examples of the aromatic ethylenically unsaturated monomer include benzyl (meth) acrylate. , Phenoxyethyl (meth) acrylate, styrene, α-methylstyrene, 2-methylstyrene, chlorostyrene, allylbenzene, ethynylbenzene and the like.

Examples of the monomer (c7) other than the monomer (c8) and the monomer (c9) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth). ) Alkyl group-containing ethylenically unsaturated monomers such as acrylate, pentyl (meth) acrylate and heptyl (meth) acrylate; nitrile group-containing ethylenically unsaturated monomers such as (meth) acrylonitrile; perfluoromethylmethyl (meth) ) Acrylic, perfluoroethyl methyl (meth) acrylate, 2-perfluorobutyl ethyl (meth) acrylate, 2-perfluorohexyl ethyl (meth) acrylate, 2-perfluorooctyl ethyl (meth) acrylate, 2-perfluoroiso Nonylethyl (meth) acrylate, 2-perfluorononylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, perfluoropropylpropyl (meth) acrylate, perfluorooctylpropyl (meth) acrylate, perfluorooctyl Perfluoroalkyl group-containing ethylenically unsaturated monomers having 1 to 20 carbon atoms such as amyl (meth) acrylate and perfluorooctylundecyl (meth) acrylate; perfluorobutylethylene, perfluorohexyl Perfluoroalkyls such as ethylene, perfluorooctylethylene and perfluorodecylethylene, perfluoroalkyl group-containing ethylenically unsaturated compounds such as alkylenes; polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (Meta) acrylate, propoxypolyethylene glycol (meth) acrylate, n-butoxypolyethylene glycol (meth) acrylate, n-pentoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxy Polypropylene glycol (meth) acrylate, ethoxypolypropylene glycol (meth) acrylate, propoxypolypropylene glycol (meth) acrylate, n-butoxypolypolyglycol (meth) acrylate, n-pentoxypolypolyglycol (meth) acrylate, phenoxypolypolyglyco Le (meth) acrylate, polytetramethylene glycol (meth) acrylate, methoxypolytetramethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, hexaethylene glycol (meth) acrylate, methoxyhexaethylene glycol (meth) acrylate Ethylene unsaturated compounds having polyether chains such as; ethylenically unsaturated compounds having polyester chains such as lactone-modified (meth) acrylates; dimethylaminoethyl methyl chloride salt (meth) acrylate, trimethyl-3- (1-) (Meta) acrylamide-1,1-dimethylpropyl) ammonium chloride, trimethyl-3- (1- (meth) acrylamidepropyl) ammonium chloride, and trimethyl-3- (1- (meth) acrylamide-1,1-dimethylethyl) ) Tethylene unsaturated compounds containing quaternary ammonium bases such as ammonium chloride; vinyl acetate, vinyl butyrate, vinyl propionate, vinyl hexanoate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, etc. Compounds: Vinyl ether-based ethylenically unsaturated monomers such as butyl vinyl ether and ethyl vinyl ether; α-olefin-based ethylenic compounds such as 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene and 1-hexadecene. Unsaturated monomers; allyl monomers such as allyl acetate and allyl cyanide; vinyl monomers such as vinyl cyanide, vinyl cyclohexane and vinyl methyl ketone; ethynyl monomers such as acetylene and ethynyl toluene. ..

Examples of the monomer (c7) other than the above-mentioned monomer (c8) and monomer (c9) include maleic acid, fumaric acid, itaconic acid, citraconic acid, and alkyl or alkenyl monoesters thereof. , Butyl β- (meth) acryloxyethyl monoester, isophthalic acid β- (meth) acryloxyethyl monoester, terephthalic acid β- (meth) acryloxyethyl monoester, succinate β- (meth) acryloxyethyl Carboxyl group-containing ethylenically unsaturated monomers such as monoester, acrylic acid, methacrylic acid, crotonic acid and carcinic acid; tertiary butyl group-containing ethylenically unsaturated monomers such as tertiary butyl (meth) acrylate; Sulphonic acid group-containing ethylenically unsaturated monomers such as vinyl sulfonic acid and styrene sulfonic acid; phosphate group-containing ethylenically unsaturated monomers such as (2-hydroxyethyl) methacrylate acid phosphate; diacetone (meth) Keto group-containing ethylenically unsaturated monos such as acrylamide, achlorine, N-vinylformamide, vinyl methyl ketone, vinyl ethyl ketone, acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl (meth) acrylate, acetoacetoxybutyl (meth) acrylate. Examples thereof include a metric (a monomer having one ethylenically unsaturated group and a keto group in one molecule).

When a keto group-containing ethylenically unsaturated monomer is used as the monomer (c7), a polyfunctional hydrazide compound having two or more hydrazide groups capable of reacting with the keto group as a cross-linking agent is mixed with the binder composition. , A tough coating can be obtained by cross-linking the keto group and the hydrazide group. As a result, it has excellent electrolytic solution resistance and binding properties.

Further, among the monomers (c7), an ethylenically unsaturated single amount having a carboxyl group, a tertiary butyl group (the tertiary butanol is eliminated by heat to become a carboxyl group), a sulfonic acid group, and a phosphoric acid group. The resin fine particles obtained by copolymerizing the bodies have the effect of improving the physical properties such as the adhesion of the base material by leaving the functional groups in the particles and on the surface even after the polymerization, and at the same time, agglomerate during synthesis. It can be preferably used because it may prevent or maintain particle stability after synthesis. The content is preferably 0.2% by weight to 20% by weight, more preferably 0.5% by weight to 10% by weight.

Some of the carboxyl group, tert-butyl group, sulfonic acid group, and phosphoric acid group may react during polymerization and be used for in-particle cross-linking. When a monomer containing a carboxyl group, a tertiary butyl group, a sulfonic acid group, and a phosphoric acid group is used, 0. It is preferably contained in an amount of 1 to 10% by mass, more preferably 1 to 5% by mass. Furthermore, these functional groups may be used for cross-linking within or between particles by reacting during drying.

For example, the carboxyl group can react with the epoxy group during polymerization and drying to introduce a crosslinked structure into the resin fine particles. Similarly, the tertiary butyl group can react with the epoxy group in the same manner as described above because the tertiary butyl alcohol is generated and the carboxyl group is formed when heat of a certain temperature or higher is applied.

For these monomers (c7), two or more of the above-mentioned monomers are used in combination in order to adjust the polymerization stability of the particles, the glass transition temperature, the film forming property, and the physical characteristics of the coating film. Can be used. Further, for example, the combined use of (meth) acrylonitrile has the effect of developing rubber elasticity.

<Method for producing crosslinked resin fine particles in (meth) acrylic emulsion preferably used in the present invention>
The crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention are synthesized by a conventionally known emulsion polymerization method.

<Emulsifier used in emulsion polymerization>
As the emulsifier used in the emulsion polymerization in the present invention, conventionally known emulsifiers such as a reactive emulsifier having an ethylenically unsaturated group and a non-reactive emulsifier having no ethylenically unsaturated group can be arbitrarily used. it can.

Reactive emulsifiers having an ethylenically unsaturated group can be further broadly classified into anionic and nonionic nonionic emulsifiers. In particular, when an anionic reactive emulsifier or a nonionic reactive emulsifier having an ethylenically unsaturated group is used, the dispersed particle size of the copolymer becomes finer and the particle size distribution becomes narrower, so that the electrolytic solution resistance is improved. Is preferable. As the anionic reactive emulsifier or nonionic reactive emulsifier having an ethylenically unsaturated group, one type may be used alone or a plurality of types may be used in combination.

Specific examples of anionic reactive emulsifiers having an ethylenically unsaturated group will be illustrated below, but the emulsifiers that can be used in the present invention are not limited to those described below.

As the emulsifier, an alkyl ether type (commercially available products, for example, Aqualon KH-05, KH-10, KH-20 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA Corporation Adecaria Soap SR-10N, SR-20N, etc. Latemuru PD-104 manufactured by Kao Corporation, etc.); Sulfocuccinate-based (commercially available products include, for example, Latemuru S-120, S-120A, S-180P, S-180A manufactured by Kao Corporation, Eleminor manufactured by Sanyo Kasei Corporation. JS-2, etc.); Alkylphenyl ether type or alkylphenyl ester type (Commercially available products include, for example, Aqualon H-2855A, H-3855B, H-3855C, H-3856, HS-05 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. , HS-10, HS-20, HS-30, ADEKA Corporation Adecaria Soap SDX-222, SDX-223, SDX-232, SDX-233, SDX-259, SE-10N, SE-20N, etc.) (Meta) acrylate sulfate ester type (commercially available products include, for example, Antox MS-60 and MS-2N manufactured by Nippon Emulsifier Co., Ltd., Eleminor RS-30 manufactured by Sanyo Kasei Kogyo Co., Ltd.); Examples of the product include H-3330PL manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., ADEKA CORPORATION PP-70 manufactured by ADEKA Corporation, and the like).

Examples of the nonionic reactive emulsifier that can be used in the present invention include alkyl ethers (commercially available products include, for example, ADEKA Corporation ADEKA Adecaria Soap ER-10, ER-20, ER-30, ER-40, etc. Latemuru PD-420, PD-430, PD-450, etc. manufactured by Kao Co., Ltd .; alkylphenyl ether type or alkylphenyl ester type (commercially available products, for example, Aqualon RN-10, RN- 20, RN-30, RN-50, ADEKA Corporation Adecaria Soap NE-10, NE-20, NE-30, NE-40, etc.); (Meta) acrylate sulfate ester type (commercially available, for example, RMA-564, RMA-568, RMA-1114, etc. manufactured by Nippon Ester Co., Ltd.) and the like.

When the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention are obtained by emulsion polymerization, the ethylenically unsaturated group is required together with the above-mentioned reactive emulsifier having an ethylenically unsaturated group. A non-reactive emulsifier that does not have the above can be used in combination. Non-reactive emulsifiers can be roughly classified into non-reactive anionic emulsifiers and non-reactive nonionic emulsifiers.

Examples of non-reactive nonionic emulsifiers include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; polyoxyethylene alkyl such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether. Phenyl ethers; sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate; polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate; polyoxyethylene monolaurate, Polyoxyethylene higher fatty acid esters such as polyoxyethylene monostearate; glycerin higher fatty acid esters such as oleic acid monoglyceride and stearate monoglyceride; polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene distyrene phenyl ether Etc. can be exemplified.

Examples of non-reactive anionic emulsifiers include higher fatty acid salts such as sodium oleate; alkylaryl sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfate esters such as sodium lauryl sulfate; polyoxyethylene lauryl ether. Polyoxyethylene alkyl ether sulfate salts such as sodium sulfate; polyoxyethylene alkylaryl ether sulfate ester salts such as polyoxyethylene nonylphenyl ether sulfate; sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, polyoxyethylene lauryl sulfosuccinic acid Alkyl sulfosuccinic acid ester salts such as sodium and derivatives thereof; polyoxyethylene distyrene phenyl ether sulfate ester salts and the like can be exemplified.

The amount of the emulsifier used in the present invention is not necessarily limited, and can be appropriately selected according to the physical characteristics required when the crosslinked resin fine particles are used as the final binder. For example, the emulsifier is usually preferably 0.1 to 30 parts by mass, more preferably 0.3 to 20 parts by mass, based on 100 parts by mass of the total ethylenically unsaturated monomer. It is more preferably in the range of 5 to 10 parts by mass.

A water-soluble protective colloid can also be used in combination with the emulsion polymerization of the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention. Examples of the water-soluble protective colloid include polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, and modified polyvinyl alcohol; cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose salt; and natural polysaccharides such as guagam. Examples include saccharides, which can be used alone or in combination of multiple species. The amount of the water-soluble protective colloid used is 0.1 to 5 parts by mass, more preferably 0.5 to 2 parts by mass, based on 100 parts by mass of the total ethylenically unsaturated monomer.

<Aqueous medium used in emulsion polymerization>
Examples of the aqueous medium used for emulsion polymerization of crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention include water, and a hydrophilic organic solvent does not impair the object of the present invention. Can be used in.

<Polymerization initiator used in emulsion polymerization>
The polymerization initiator used to obtain the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention is not particularly limited as long as it has the ability to initiate radical polymerization, and is known. An oil-soluble polymerization initiator or a water-soluble polymerization initiator can be used.

The oil-soluble polymerization initiator is not particularly limited, and for example, benzoyl peroxide, tert-butylperoxybenzoate, tert-butylhydroperoxide, tert-butylperoxy (2-ethylhexanoate), tert-butylper. Organic peroxides such as oxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide; 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4- Examples thereof include azobis compounds such as dimethylvaleronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 1,1'-azobis-cyclohexane-1-carbonitrile. These can be used alone or in admixture of two or more. It is preferable to use 0.1 to 10.0 parts by mass of these polymerization initiators with respect to 100 parts by mass of the ethylenically unsaturated monomer.

In the present invention, it is preferable to use a water-soluble polymerization initiator, for example, ammonium persulfate, potassium persulfate, hydrogen peroxide, 2,2'-azobis (2-methylpropion amidine) dihydrochloride, etc., which are conventionally known. Can be preferably used. Further, when carrying out emulsion polymerization, a reducing agent can be used in combination with the polymerization initiator, if desired. This makes it easy to accelerate the emulsion polymerization rate and to carry out the emulsion polymerization at a low temperature. Examples of such reducing agents include reducing organic compounds such as ascorbic acid, elsorbic acid, tartrate acid, citric acid, glucose, and metal salts such as formaldehyde sulfoxylate, sodium thiosulfite, sodium sulfite, sodium bisulfite, and meta. Examples thereof include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, longalite, and thiourea dioxide. It is preferable to use an amount of 0.05 to 5.0 parts by mass of these reducing agents with respect to 100 parts by mass of the total ethylenically unsaturated monomer.

<Conditions for emulsion polymerization>
It should be noted that the polymerization can be carried out not only by the above-mentioned polymerization initiator but also by a photochemical reaction, irradiation or the like. The polymerization temperature is equal to or higher than the polymerization start temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, the temperature may usually be about 70 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

<Other materials used in the reaction>
Further, if necessary, as a buffer, sodium acetate, sodium citrate, sodium bicarbonate, etc., and as a chain transfer agent, octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan, etc. , T-dodecyl mercaptans and other mercaptans can be used in appropriate amounts.

When a monomer having an acidic functional group such as a carboxyl group-containing ethylenically unsaturated monomer is used for the polymerization of the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention, before the polymerization It can be neutralized with a basic compound after polymerization. Upon neutralization, it can be neutralized with ammonia or alkylamines such as trimethylamine, triethylamine, butylamine; alcoholamines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine, aminomethylpropanol; bases such as morpholine. .. However, highly volatile bases are highly effective in drying properties, and preferred bases are aminomethylpropanol and ammonia.

<Characteristics of crosslinked resin fine particles in (meth) acrylic emulsion preferably used in the present invention>
(Glass-transition temperature)
The glass transition temperature (hereinafter, also referred to as Tg) of the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention is preferably −50 to 70 ° C., further preferably -30 to 30 ° C. preferable. The glass transition temperature is a value obtained by using a DSC (Differential Scanning Calorimetry).

The glass transition temperature can be measured by DSC (Differential Scanning Calorimetry) as follows. Approximately 2 mg of the dried resin of the crosslinked resin fine particles is weighed on an aluminum pan, the test container is set in the DSC measurement holder, and the endothermic peak of the chart obtained under the heating condition of 10 ° C./min is read. The peak temperature at this time is defined as the glass transition temperature of the present invention.

(Particle structure)
Further, the particle structure of the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention can be a multilayer structure, so-called core-shell particles. For example, by localizing a resin in which a monomer having a functional group is mainly polymerized in the core portion or the shell portion, or by providing a difference in Tg and composition between the core and the shell, curability and drying are performed. It is possible to improve the property, film forming property, and mechanical strength of the binder.

(Particle size)
The average particle size of the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention is preferably 10 to 500 nm from the viewpoint of catalyst binding and particle stability, and is preferably 30. More preferably, it is ~ 300 nm. Further, if a large amount of coarse particles exceeding 1 μm is contained, the stability of the particles is impaired. Therefore, the amount of coarse particles exceeding 1 μm is preferably 5% by mass or less at most. The average particle size in the present invention represents the volume average particle size and can be measured by a dynamic light scattering method.

The average particle size can be measured by the dynamic light scattering method as follows. The crosslinked resin fine particle dispersion is diluted 200 to 1000 times with water depending on the solid content. Approximately 5 ml of the diluted solution is injected into a cell of a measuring device [Microtrac manufactured by Nikkiso Co., Ltd.], and the measurement is performed after inputting the refractive index conditions of the solvent (water in the present invention) and the resin according to the sample. The peak of the volumetric particle size distribution data (histogram) obtained at this time is taken as the average particle size of the present invention.

<Uncrosslinked compound (E) added to polymerized resin fine particles>
In addition to the crosslinked resin fine particles, the (meth) acrylic emulsion preferably used in the present invention further comprises an uncrosslinked epoxy group-containing compound, an uncrosslinked amide group-containing compound, an uncrosslinked hydroxyl group-containing compound, and an uncrosslinked hydroxyl group-containing compound. It is preferable to include at least one uncrosslinked compound (E) [hereinafter, may be referred to as compound (E)] selected from the group consisting of uncrosslinked oxazoline group-containing compounds. Compound (E) is a compound that disperses without being dissolved in an aqueous liquid medium.

The “uncrosslinked functional group-containing compound” as compound (E) is the inside of a (meth) acrylic emulsion preferably used in the present invention, such as the monomer contained in the monomer group (C1). Unlike a compound that forms a crosslinked structure (three-dimensional crosslinked structure), it refers to a compound that is added after the resin fine particles are emulsified and polymerized (polymer formation) (not involved in the internal crosslink formation of the resin fine particles). That is, "uncrosslinked" means that it is not involved in the formation of the internal crosslinked structure (three-dimensional crosslinked structure) of the (meth) acrylic emulsion preferably used in the present invention.

The (meth) acrylic emulsion preferably used in the present invention has a crosslinked structure to ensure electrolytic solution resistance, and by using the compound (E), the epoxy group in the compound (E), At least one functional group selected from an amide group, a hydroxyl group, and an oxazoline group can contribute to the adhesion to the substrate or other electrode constituent materials. Furthermore, by adjusting the crosslinked structure and the amount of functional groups, it is possible to obtain a mixture ink having excellent durability of the enzyme sensor.

The crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention need to be crosslinked inside the particles. Electrolyte resistance can be ensured by appropriately adjusting the cross-linking inside the particles. Further, at least one selected from the group consisting of a non-crosslinked epoxy group-containing compound, an uncrosslinked amide group-containing compound, an uncrosslinked hydroxyl group-containing compound, and an uncrosslinked oxazoline group-containing compound in functional group-containing crosslinked resin fine particles. By adding the uncrosslinked compound (E), an epoxy group, an amide group, a hydroxyl group or an oxazoline group can act on the base material to effectively improve the adhesion to the base material and other electrode constituent materials. it can. Since the functional group contained in the compound (E) is stable even when stored for a long period of time or when the electrode is manufactured, the effect of adhesion to the substrate is large even when used in a small amount. Furthermore, it is also excellent in storage stability. The compound (E) may react with a functional group in the crosslinked resin fine particles for the purpose of adjusting the flexibility and electrolyte resistance of the binder, but it may react with the functional group in the crosslinked resin fine particles containing a functional group. If the functional groups in the compound (E) are used too much for the reaction, the functional groups that can interact with the base material or the electrode are reduced. Therefore, the reaction between the crosslinked resin fine particles in the (meth) acrylic emulsion preferably used in the present invention and the compound (E) does not impair the adhesion to the base material or other electrode constituent materials. There must be. When some of the functional groups contained in the compound (E) are used in the cross-linking reaction (when the compound (E) is a polyfunctional compound), the degree of cross-linking of these functional groups can be adjusted. A balance between electrolyte resistance and adhesion can be achieved.

<Uncrosslinked epoxy group-containing compound>
Examples of the uncrosslinked epoxy group-containing compound include epoxy group-containing ethylenically unsaturated monomers such as glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate; Radical polymerization resin obtained by polymerizing an ethylenically unsaturated monomer containing a metric; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol Diglycidyl ether, trimethylolpropan triglycidyl ether, diglycidyl aniline, N, N, N', N'-tetraglycidyl-m-xylylene diamine, 1,3-bis (N, N'-diglycidyl aminomethyl) Polyfunctional epoxy compounds such as cyclohexane; epoxy resins such as bisphenol A-epichlorohydrin type epoxy resin and bisphenol F-epichlorohydrin type epoxy resin can be mentioned.

Among the epoxy group-containing compounds, epoxy resins such as bisphenol A-epichlorohydrin type epoxy resin and bisphenol F-epichlorohydrin type epoxy resin, and ethylenia containing epoxy group-containing ethylenically unsaturated monomers are contained. A radical polymerization type resin obtained by polymerizing a saturated monomer is preferable. Epoxy-based resins can be expected to have a synergistic effect of improving electrolytic solution resistance by having a bisphenol skeleton and improving substrate adhesion by the hydroxyl groups contained in the skeleton. Further, the radical polymerization resin obtained by polymerizing an ethylenically unsaturated monomer containing an epoxy group-containing ethylenically unsaturated monomer has more epoxy groups in the resin skeleton to improve substrate adhesion. Further, by improving the resin, it can be expected to have an effect of improving the electrolytic solution resistance as compared with the monomer.

<Uncrosslinked amide group-containing compound>
Examples of the uncrosslinked amide group-containing compound include primary amide group-containing compounds such as (meth) acrylamide; N-methylol acrylamide, N, N-di (methylol) acrylamide, and N-methylol-N-methoxymethyl (meth). ) Alkyrol (meth) acrylamide compounds such as acrylamide; N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) ) Monoalkoxy (meth) acrylamide compounds such as acrylamide and N-pentoxymethyl- (meth) acrylamide; N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N -Di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) metaacrylamide, N, N-di Dialkoxy such as (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) metaacrylamide, N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) metaacrylamide. (Meta) acrylamide compounds; Dialkylamino (meth) acrylamide compounds such as N, N-dimethylaminopropylacrylamide and N, N-diethylaminopropylacrylamide; Dialkyls such as N, N-dimethylacrylamide and N, N-diethylacrylamide (Meta) acrylamide compound; Keto group-containing (meth) acrylamide compound such as diacetone (meth) acrylamide, etc. The above amide group-containing ethylenically unsaturated monomer; Examples thereof include a radical polymerization type resin obtained by polymerizing an ethylenic unsaturated monomer containing acrylamide.

Among the amide group-containing compounds, a radical polymerization resin obtained by polymerizing an ethylenically unsaturated monomer containing an amide group-containing ethylenically unsaturated monomer such as acrylamide is particularly preferable. By having more amide groups in the resin skeleton, the adhesion to the base material can be improved, and by using the resin, the effect of improving the electrolytic solution resistance as compared with the monomer can be expected.

<Uncrosslinked hydroxyl group-containing compound>
Examples of the uncrosslinked hydroxyl group-containing compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate 4-hydroxyvinylbenzene, and the like. Hydroxyl-containing ethylenically unsaturated monomer such as 1-ethynyl-1-cyclohexanol and allyl alcohol; radical polymerization obtained by polymerizing the ethylenically unsaturated monomer containing the hydroxyl group-containing ethylenically unsaturated monomer. Series resins; linear aliphatic diols such as ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol; propylene glycol, neopentyl glycol , 3-Methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol and other branched chain aliphatic diols; 1,4-bis (hydroxymethyl) cyclohexane and other cyclic diols can give.

Among the hydroxyl group-containing compounds, a radical polymerization resin obtained by polymerizing an ethylenically unsaturated monomer containing a hydroxyl group-containing ethylenically unsaturated monomer, or cyclic diols is particularly preferable. The radical polymerization resin obtained by polymerizing an ethylenically unsaturated monomer containing a hydroxyl group-containing ethylenically unsaturated monomer improves the adhesion to the base material by having more hydroxyl groups in the resin skeleton. Further, since it is a resin, it can be expected to have an effect of improving electrolytic solution resistance as compared with a monomer. Further, the cyclic diols can be expected to have an effect of improving the electrolytic solution resistance by having a cyclic structure in the skeleton.

<Uncrosslinked oxazoline group-containing compound>
Examples of the uncrosslinked oxazoline group-containing compound include 2'-methylenebis (2-oxazoline), 2,2'-ethylenebis (2-oxazoline), and 2,2'-ethylenebis (4-methyl-2-oxazoline). ), 2,2'-propylene bis (2-oxazoline), 2,2'-tetramethylene bis (2-oxazoline), 2,2'-hexamethylene bis (2-oxazoline), 2,2'-octamethylene Bis (2-oxazoline), 2,2'-p-phenylene bis (2-oxazoline), 2,2'-p-phenylene bis (4,4'-dimethyl-2-oxazoline), 2,2'-p -Phenylenebis (4-methyl-2-oxazoline), 2,2'-p-Phenylenbis (4-phenyl-2-oxazoline), 2,2'-m-Phenylenebis (2-oxazoline), 2,2 '-M-Phenylenebis (4-methyl-2-oxazoline), 2,2'-m-Phenylenebis (4,4'-dimethyl-2-oxazoline), 2,2'-m-Phenylenebis (4- Phenylenebis-2-oxazoline), 2,2'-o-phenylenebis (2-oxazoline), 2,2'-o-phenylenebis (4-methyl-2-oxazoline), 2,2'-bis (2) -Oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4-ethyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline) ), Further, an oxazoline group-containing radical polymerization resin and the like can be mentioned.

Among the oxazoline group-containing compounds, in particular, a phenylenebis-type oxazoline compound such as 2'-p-phenylenebis (2-oxazoline) or an ethylenically unsaturated monomer containing an oxazoline group-containing ethylenically unsaturated monomer. A radical polymerization resin obtained by polymerizing the above is preferable. The phenylene bis-type oxazoline compound has an effect of improving the electrolyte resistance by having a phenyl group in the skeleton. Further, the radical polymerization type resin obtained by polymerizing an ethylenically unsaturated monomer containing an oxazoline group-containing ethylenically unsaturated monomer has more oxazoline groups in the resin skeleton to improve substrate adhesion. By improving the resin, the electrolytic solution resistance can be improved as compared with the monomer.

(Amount of compound (E) added, molecular weight)
The compound (E) is preferably added in an amount of 0.1 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the solid content of the crosslinked resin fine particles. Further, two or more kinds of the compound (E) can be used in combination.

The molecular weight of compound (E) is not particularly limited, but the mass average molecular weight is preferably 1,000 to 1,000,000, more preferably 5,000 to 500,000. The mass average molecular weight is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method.

<Aqueous liquid medium>
Water is preferably used as the aqueous liquid medium used in the present invention, but if necessary, for example, a liquid medium compatible with water is used in order to improve the coatability on the conductive substrate. You may.
Liquid media compatible with water include alcohols, glycols, cellosolves, aminoalcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, and phosphoric acid esters. , Ethers, nitriles and the like, and may be used as long as they are compatible with water.

Further, a dispersant, a thickener, a film forming aid, a defoaming agent, a leveling agent, a preservative, a pH adjuster and the like can be added to the mixture ink as needed. In particular, since it may be difficult to obtain the viscosity and dispersion stability of the mixture ink only with the water-based resin fine particles, it is preferable to contain a thickener or a dispersant.

The dispersant and thickener are preferably water-soluble resins, and are not particularly limited, but for example, acrylic resins, polyurethane resins, polyester resins, polyamide resins, polyimide resins, polyallylamine resins, phenol resins, and the like. Examples thereof include polymer compounds containing polysaccharide resins such as epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, formaldehyde resin, silicon resin, fluororesin and carboxymethyl cellulose. Further, as long as it is water-soluble, a modified product, a mixture, or a copolymer of these resins may be used. These may be used alone or in combination of two or more.

<Preparation method of electrode forming composition for enzyme sensor>
There is no particular limitation on the method for preparing the electrode forming composition (mixture ink). In preparation, each component may be dispersed at the same time, or the conductive material and / or oxygen reductase may be dispersed in an aqueous liquid medium, and then the aqueous resin fine particles may be added, and the conductive material and / or oxidoreductase to be used may be added. It can be optimized by enzymes, aqueous resin fine particles, and aqueous liquid medium. Further, the enzyme may be supported after the electrode is first formed of the composition composed of the conductive material, the aqueous resin fine particles, and the aqueous liquid medium.

For example, the conductive material and / or the oxygen reduction catalyst is 5 to 99 parts by mass, preferably 10 to 95 parts by mass, and the aqueous resin fine particles are 0.01 to 80 parts by mass with respect to 100 parts by mass of the solid content of the mixture ink of the present invention. It is by mass, preferably 0.02 to 60 parts by mass.

<Disperser / Mixer>
As an apparatus used for obtaining a mixture ink for an enzyme sensor, a disperser or a mixer usually used for pigment dispersion or the like can be used.

For example, mixers such as disper, homomixer, or planetary mixer; homogenizers such as "Clearmix" manufactured by M-Technique or "Philmix" manufactured by PRIMIX; paint conditioner (manufactured by Red Devil), ball mill, sand mill. (Symmal Enterprises "Dyno Mill" etc.), Atwriter, Pearl Mill (Eirich "DCP Mill" etc.), or media type disperser such as Coball Mill; Wet Jet Mill (Genus "Genus PY", Sugino) Medialess dispersers such as Machine's "Starburst", Nanomizer's "Nanomizer"), M-Technique's "Claire SS-5", or Nara Machinery's "MICROS"; or other roll mills, etc. However, it is not limited to these.

<Electrodes / base materials>
The enzyme sensor forms electrodes on the substrate. The base material used for the enzyme sensor is not particularly limited, and examples thereof include a conductive base material and a non-conductive base material. Examples of the conductive base material include a conductive layer made of a conductive carbon material such as carbon paper and carbon cloth, a metal foil, and a metal mesh. Examples of the non-conductive base material include papers, cloths, resin films, etc. Further, a conductive carbon composition or a conductive polymer such as polyaniline, polyacetylene, polypyrrole, polythiophene, etc. is printed / applied on the surface thereof. A dried material, a material obtained by sputtering a conductive material such as a metal, or a material in which they are used in combination may be used. Further, the printing and coating method of the composition is not particularly limited, and a general method can be applied.

<Enzyme sensor>
The enzyme sensor of the present invention is composed of at least an working electrode and a counter electrode as an electrode, and may further include a reference electrode. Further, if necessary, a spacer, a cover, or the like for introducing a sample such as blood into the electrode may be provided.
A plurality of electrodes used for an enzyme sensor may be produced by forming conductive layers on different non-conductive substrates, or may form a conductive layer for each electrode on the same non-conductive substrate. An electrode may be produced by forming a non-conductive portion after placing a conductive layer on the same non-conductive base material. Further, the electrode may be produced by forming a metal layer on a non-conductive base material by metal sputtering or the like in advance and then forming a conductive layer of each electrode. When the reference electrode is installed, it is produced by, for example, further laminating silver, silver chloride, or the like on the upper part of the conductive layer. For the lead portion of each electrode, a method of forming a metal layer by metal sputtering or the like, a method of extending the conductive layer and using it, a method of further forming a metal layer by metal sputtering or the like on the upper or lower part of the extended conductive layer, etc. It can be exemplified. Further, any of the electrodes of the working electrode, the counter electrode, and the reference electrode may be produced by the above method.

As a method of installing the oxidoreductase or the mediator, a method of incorporating the oxidoreductase or the mediator as needed in the upper part of these electrodes or the upper part and / or the inside of the working electrode, the oxidoreductase or as necessary Examples thereof include a method of forming a mixture layer to which a mediator is added, a method of dispersing the mixture in the mixture ink in advance, coating and printing, and then drying and installing the mixture in the electrode. When forming a mixture layer containing an oxidoreductase or a mediator, a hydrophilic compound and / or a hydrophilic resin may be mixed.

As described above, the enzyme sensor selectively oxidizes or reduces a specific component contained in a biological sample such as blood or food, depending on the substrate specificity of the enzyme, and qualitatively or quantifies it from the current value or the like. Applications of enzyme sensors include, for example, organic matter sensors for various organic substances, biological sensors for organic substances and body fluids in biological samples such as blood, sweat, urine, stool, tears, saliva, and exhaled breath, and water. Moisture sensor, food sensor for fruits and sugar in food, IoT sensor, environmental sensor for organic matter in the environment such as air, rivers and soil, animals and plants for animals, insects and plants Examples include sensors. Examples of biological sensors include a blood glucose level sensor that senses sugar in blood, a urine sugar level sensor that senses sugar in urine, a fatigue sensor and heat stroke sensor that senses lactic acid level in sweat, and sweat and urine. Examples include a sweating sensor and a urine sensor that sense the moisture inside. Further, as an application as a wearable sensor for a living body, for example, a urination sensor or a urine sugar level sensor in which a sensor is installed in a diaper, a percutaneous sticking type sweating sensor, a heat stroke sensor, and the like can be mentioned.

<Ion conductor>
The enzyme sensor of the present invention may use an ion conductor that conducts ions between electrodes. The form of the ionic conductor is not particularly limited as long as it has ionic conductivity. As the ionic conductor, an electrolyte that dissolves in a liquid, a solid polymer electrolyte, or the like may be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples do not limit the scope of rights of the present invention at all. Unless otherwise specified, "parts" in Examples and Comparative Examples means "parts by mass", and "%" means "% by mass".

<Preparation of aqueous resin fine particle dispersion>
[Synthesis Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a recirculator, 40 parts of ion-exchanged water and 0.2 part of ADEKA CORPORATION SR-10 (manufactured by ADEKA Corporation) as a surfactant are charged separately. 49 parts of methyl methacrylate, 50 parts of butyl acrylate, 0.5 part of acrylic acid, 0.5 part of 3-methacryloxypropyltrimethoxysilane, 53 parts of ion-exchanged water and ADEKA CORPORATION SR-10 as a surfactant (ADEKA Corporation) (Manufactured) 1.8 parts of the pre-emulsion mixed in advance was further added. After raising the internal temperature to 70 ° C. and sufficiently substituting with nitrogen, 10% of 10 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization. After keeping the inside of the reaction system at 70 ° C. for 5 minutes, the rest of the pre-emulsion and the rest of the 5% aqueous solution of potassium persulfate were added dropwise over 3 hours while keeping the internal temperature at 70 ° C., and stirring was continued for another 2 hours. .. After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. 25% aqueous ammonia was added to adjust the pH to 8.5, and the solid content was adjusted to 40% with ion-exchanged water to obtain an aqueous resin fine particle dispersion. The solid content was determined from the baking residue at 150 ° C. for 20 minutes.

<Production of compound (E) [Production of epoxy group-containing compound]>
[Manufacturing Example 1]
20 parts of isopropyl alcohol and 20 parts of water were charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and 40 parts of methyl methacrylate, 40 parts of methyl acrylate, and 20 parts of glycidyl methacrylate were separately added to the dropping tank 1. Further, 2 parts of potassium persulfate was dissolved in 30 parts of isopropyl alcohol and 30 parts of water and charged into the dropping tank 2. After raising the internal temperature to 80 ° C. and sufficiently replacing the nitrogen with nitrogen, the dropping tanks 1 and 2 were dropped over 2 hours to carry out polymerization. After completion of the dropping, stirring was continued for 1 hour while maintaining the internal temperature at 80 ° C., and after confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C., and the epoxy having a solid content of 40%. A group-containing compound (methyl methacrylate / methyl acrylate / glycidyl methacrylate copolymer) solution was obtained. The solid content was determined from the baking residue at 150 ° C. for 20 minutes.

<Production of compound (E) [Production of amide group-containing compound]>
[Manufacturing Example 2]
90 parts of water is charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and 20 parts of acrylamide is separately dissolved in the dropping tank 1 and 2 parts of potassium persulfate is dissolved in 90 parts of water. It was charged in the dropping tank 2. After raising the internal temperature to 80 ° C. and sufficiently replacing the nitrogen with nitrogen, the dropping tanks 1 and 2 were dropped over 2 hours to carry out polymerization. After completion of the dropping, stirring was continued for 1 hour while maintaining the internal temperature at 80 ° C., and after confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. and amide having a solid content of 40%. A group-containing compound (polyacrylamide) solution was obtained. The solid content was determined from the baking residue at 150 ° C. for 20 minutes.

[Manufacturing Example 3]
40 parts of water was charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and 40 parts of 2-ethylhexyl acrylate, 40 parts of styrene, and 20 parts of dimethylacrylamide were separately added to the dropping tank 1 and excess. Two parts of potassium sulfate were dissolved in 60 parts of water and charged into the dropping tank 2. After raising the internal temperature to 80 ° C. and sufficiently replacing the nitrogen with nitrogen, the dropping tanks 1 and 2 were dropped over 2 hours to carry out polymerization. After completion of the dropping, stirring was continued for 1 hour while maintaining the internal temperature at 80 ° C., and after confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. and amide having a solid content of 40%. A group-containing compound (2-ethylhexyl acrylate / styrene / dimethylacrylamide copolymer) solution was obtained. The solid content was determined from the baking residue at 150 ° C. for 20 minutes.

<Production of compound (E) [Production of hydroxyl group-containing compound]>
[Manufacturing Example 4]
20 parts of isopropyl alcohol and 20 parts of water are charged in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a refluxer, and 40 parts of methyl methacrylate, 40 parts of butyl acrylate, and 20 parts of 2-hydroxyethyl methacrylate are separately added dropwise. In tank 1, 2 parts of potassium persulfate was dissolved in 30 parts of isopropyl alcohol and 30 parts of water and charged into the dropping tank 2. After raising the internal temperature to 80 ° C. and sufficiently replacing the nitrogen with nitrogen, the dropping tanks 1 and 2 were dropped over 2 hours to polymerize. After completion of the dropping, stirring was continued for 1 hour while maintaining the internal temperature at 80 ° C., and after confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C., and a hydroxyl group having a solid content of 40% was obtained. A solution of the containing compound (methyl methacrylate / butyl acrylate / 2-hydroxyethyl methacrylate copolymer) was obtained. The solid content was determined from the baking residue at 150 ° C. for 20 minutes.

[Synthesis Examples 2 to 16]
The composition shown in Table 1 was synthesized in the same manner as in Synthesis Example 1 to obtain aqueous resin fine particle dispersions of Synthesis Examples 2 to 6. Further, the compound (E) was added to 100 parts by mass of the solid content of the aqueous resin fine particle dispersion with the compounding composition shown in Table 2 to obtain the aqueous resin fine particle dispersions of Synthesis Examples 7 to 12. Further, Synthesis Examples 13 to 16 were synthesized in the same manner as in Synthesis Example 1 with the compounding composition shown in Table 3. However, in Synthesis Examples 15 and 16, the resin aggregated during emulsion polymerization, and the desired resin fine particles could not be obtained.

[Example 1]
Furness Black VULCAN® XC72 (manufactured by CABOT) 4.8 parts as conductive material, 48.2 parts of water as aqueous liquid medium, 2 parts of polyvinylpyrrolidone aqueous solution (solid content 20%) as dispersant, thickener 40 parts (solid content 2%) of the carboxymethyl cellulose aqueous solution was put into a mixer to mix, and then put into a sand mill to disperse. Then, 5 parts (solid content 40%) of the aqueous resin fine particle dispersion described in Synthesis Example 1 was added and mixed with a disper, and water was appropriately added to adjust the viscosity to obtain a mixed material ink.
The mixture ink was applied to a PET base material (Lumirror (manufactured by Toray Industries, Inc.)) having a thickness of 100 μm as a non-conductive base material using a doctor blade, and then heat-dried to obtain a conductive layer.
The obtained conductive layer was cut out to a size of 10 × 30 mm, and the area other than the lower portion of 5 × 5 mm was masked with tape. A methanol solution of ferrocene as a mediator and an aqueous solution of glucose oxidase as an enzyme were added dropwise to a 5 × 5 mm region not subjected to masking treatment, and the mixture was air-dried to support the mediator and the enzyme to obtain an electrode for an enzyme sensor.

[Examples 2 to 21, Comparative Examples 1 to 3]
Using the conductive material, oxidoreductase, aqueous resin fine particles, and aqueous liquid medium shown in Table 4, mixed material inks and electrodes were prepared in the same manner as in Example 1, and Examples 2 to 21 and Comparative Examples 1 to 3 were prepared. Electrode was obtained.

[Examples 22 and 23, Comparative Examples 4 and 5]
Using the conductive material, oxidoreductase, aqueous resin fine particles, and aqueous liquid medium shown in Table 5, mixture inks and electrodes were prepared in the same manner as in Example 1, and Examples 22 and 23 and Comparative Examples 4 and 5 were prepared. Electrode was obtained.

[Example 24]
Furness Black VULCAN® XC72 (manufactured by CABOT) 4.8 parts as a conductive material, 48.2 parts of water as an aqueous liquid medium, and 2 parts of an aqueous polyvinylpyrrolidone solution (solid content 20%) as a thickener. 40 parts (solid content 2%) of the carboxymethyl cellulose aqueous solution was put into a mixer and mixed, and further put into a sand mill to disperse. Then, 5 parts (40% solid content) of the aqueous resin fine particle dispersion described in Synthesis Example 2, 0.5 part of ferrocene as a mediator, and 0.5 part of glucose oxidase as an oxidoreductase are added and mixed, and water is appropriately added. Was added to adjust the viscosity to obtain a mixture ink.
The mixture ink was applied onto a PET base material (Lumirror (manufactured by Toray Industries, Inc.)) having a thickness of 100 μm as a non-conductive base material, and then dried to obtain an electrode for an enzyme sensor.

[Examples 25 to 31, Comparative Example 6]
Using the conductive material, the aqueous resin fine particles, and the aqueous liquid medium shown in Table 6, mixed material inks and electrodes were prepared in the same manner as in Example 24, and the electrodes of Examples 25 to 31 and Comparative Example 6 were obtained.

[Examples 32 and 33, Comparative Example 7]
Using the conductive material, oxidoreductase, aqueous resin fine particles, and aqueous liquid medium shown in Table 7, mixed material inks and electrodes were prepared in the same manner as in Example 24, and the electrodes of Examples 32 and 33 and Comparative Example 7 were prepared. Got

<Evaluation of electrode adhesion>
The electrodes prepared above were cut in vertical and horizontal grids at 2 mm intervals using a knife to reach a depth from the electrode surface to the base material. Adhesive tape was attached to this notch and immediately peeled off, and the degree of detachment of the coated surface was visually determined. The evaluation criteria are shown below. The results are shown in Tables 4-7.

◯: “Almost no peeling (level without practical problem)”
○ △: "Approximately 80% peeling (problem but usable level)"
Δ: "Half peeling"
×: "Peeling in most parts"

<Electrochemical evaluation>
The enzyme sensor electrode prepared above is charged with a working electrode, a counter electrode (platinum coil electrode), a reference electrode (Ag / AgCl electrode), and a 0.1 M phosphate buffer solution (pH 7.0) as an electrolytic solution, and a reaction substrate (sensing target). D-glucose was added so as to be 20 mM, a potential of 0.5 V (vsAg / AgCl) was applied, and the current value after 10 seconds was measured. As shown in Tables 4 to 7, the evaluation of the current value was performed by the percentage (%) of the current value in each example with respect to the current value of Comparative Example 1, Comparative Example 4, Comparative Example 6, and Comparative Example 7. It can be said that the larger the current value measured by the electrode for the enzyme sensor, the easier it is to detect the substance to be sensed, and the higher the sensitivity.

Examples 1 to 14 and Examples 19 to 21 showed an adhesion and a current value equal to or higher than those of Comparative Examples 1 and 3. Similarly, Examples 24 to 26 and Examples 30 and 31 showed an adhesion and a current value equal to or higher than those of Comparative Example 6. Further, Examples 22 to 23 and Examples 32 and 33 showed an adhesion and a current value equal to or higher than those of Comparative Examples 4 and 7. Among them, the examples using the (meth) acrylic emulsion polymer, which is the aqueous resin fine particles, were excellent in both adhesion and output performance. Further, as compared with Examples 15 to 18 and Examples 27 to 29, the current value was further improved by using Ketjen Black having a large specific surface area. On the other hand, when Ketjen Black was used as in Comparative Example 2, the adhesiveness tended to be inferior, but when the water-based resin fine particles were used, the current value was improved and the adhesiveness was also improved to a usable level. It was also suggested that since sufficient adhesion can be ensured by using the water-based resin fine particles, the total amount of resin in the electrode can be reduced, and the sensitivity can be further improved and the cost can be further reduced.

<Sensing using an enzyme sensor>
For the enzyme sensor electrode of Example 4, 10 seconds after applying a potential of 0.5 V (vsAg / AgCl) in a 0.1 M phosphate buffer solution containing 0.01 M, 0.05 M, and 0.1 M glucose. When the current value of was measured, a correlation was found between the glucose concentration and the current value. Further, for the enzyme sensor of Example 23, 10 seconds after applying a potential of 0.5 V (vsAg / AgCl) in a 0.1 M phosphate buffer solution containing 0.01 M, 0.05 M, and 0.1 M lactic acid. When the current value was measured and the current value was confirmed, a correlation was found between the lactic acid concentration and the current value. Since the change in the current value depending on the concentration of the sensing object was obtained, its use as a sensor was suggested.

Claims (9)

A composition for forming an enzyme sensor electrode containing a conductive material and / or an oxidoreductase, aqueous resin fine particles, and an aqueous liquid medium. The composition for forming an enzyme sensor electrode according to claim 1, wherein the aqueous resin fine particles contain an acrylic emulsion and / or a methacrylic emulsion. The composition for forming an enzyme sensor electrode according to claim 1 or 2, wherein the aqueous resin fine particles contain crosslinked resin fine particles. The composition for forming an enzyme sensor electrode according to any one of claims 1 to 3, wherein the conductive material is a carbon material. The composition for forming an enzyme sensor electrode according to any one of claims 1 to 4, further comprising a water-soluble dispersant. An enzyme sensor electrode formed from the enzyme sensor electrode forming composition according to any one of claims 1 to 5. The electrode for an enzyme sensor according to claim 6, further comprising one or more kinds of redox enzymes. The enzyme sensor electrode forming composition according to any one of claims 1 to 5, or an enzyme sensor comprising the enzyme sensor electrode according to any one of claims 6 to 7. The enzyme sensor according to claim 8, wherein the substance to be sensed is selected from glucose, fructose, and lactic acid.