JP2014215150A - Electrode for biosensor, biosensor, conductive resin composition for biosensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for a biosensor with excellent conductivity in an electrode system and a wiring part, at an inexpensive price.SOLUTION: An electrode for a biosensor includes: a support base material; and an electrode system and a wiring part formed on the support base material. The electrode system and the wiring part have: a conductive resin layer formed on the support base material and including metal microparticles made of a base metal with a corrosion resistance; carbon nano-tubes; and a binder resin. The content of the carbon nano-tubes in the conductive resin layer is within a range of 1-20 mass%.

Description

  The present invention relates to a biosensor for measuring a specific component in a liquid sample such as blood.

  Biosensors using electrochemical detection means have been put into practical use as a method for quickly and easily measuring the concentration and the like of a specific component in a biological sample such as blood. A biosensor generally includes an electrode system including a working electrode and a counter electrode, an enzyme, and an electron acceptor as basic components. An example of such a biosensor is a glucose sensor that electrochemically quantifies glucose in blood.

  In the glucose sensor, the enzyme selectively oxidizes glucose in blood to produce gluconic acid, and simultaneously reduces the electron acceptor to produce a reduced form. By applying a constant voltage to the reductant with an electrode system, the reductant is oxidized again, and current is generated at that time. Since this current depends on the glucose concentration in the blood, glucose in the blood can be quantified.

In addition, a bacterial wall toxin called endotoxin is generally known. In recent years, methods for measuring the concentration of endotoxin using an electrochemical method have been studied. Endotoxin is a toxic substance that constitutes the outer membrane of Gram-negative bacteria such as Escherichia coli and Salmonella. If this endotoxin is mixed in blood or the like even in a very small amount (for example, in the order of ng / mL), it may cause a shock symptom or the like, resulting in the worst death. However, endotoxins are widely present in the air. For this reason, inspections such as the presence of endotoxins in pharmaceuticals such as dialysate are being carried out.
For example, a technique is known in which an electrode is placed in a mixture of an analyte and a reagent, and measurement based on differential pulse voltammetry (DPV) is performed (see Patent Document 1).

In biosensors, conductive materials such as noble metal materials such as platinum and gold and carbon materials have been generally used as electrode materials. These electrode materials have a property that they are hardly oxidized or reduced even when they come into contact with moisture in the sample or an electron acceptor (mediator). However, noble metal materials such as platinum and gold are expensive and have a problem of increasing costs. In addition, although carbon materials can form electrodes at low cost, there is a problem that it is difficult to stably form carbon electrodes exhibiting desired conductivity, and the performance of individual biosensors tends to vary.
Therefore, in place of the electrode material of the biosensor described above, it has been studied to use a metal material that is relatively inexpensive and difficult to be oxidized and reduced, such as nickel (for example, Patent Document 2).

  By the way, conventionally, as a method for forming an electrode system in a biosensor using a metal material, for example, a metal film is formed on the entire surface of a substrate by vacuum deposition, sputtering, plating, metal foil adhesion, etc. A patterning method has been proposed (for example, Patent Document 3). However, in such a method, a large amount of metal is used and unnecessary portions of the metal film are removed, so that there is a problem that costs increase and a manufacturing process is complicated.

JP 2012-127695 A JP 2008-45877 A JP2012-58168A

  A medical biosensor represented by a glucose sensor or the like is disposable, and a patient uses a new biosensor for the next examination. Such a disposable biosensor is mainly desired to be able to be manufactured at low cost.

  Therefore, the present inventor has made various studies on a method for manufacturing an inexpensive biosensor, and a conductive resin layer containing metal fine particles composed of a base metal having corrosion resistance such as nickel and a binder resin (see FIG. 7 described later). ) To form the electrode system and the wiring part by a printing method, it is difficult for the conductive resin layer having the above composition to exhibit conductivity sufficient to function as the electrode system and the wiring part of the biosensor. I found out. The present inventor who has obtained the above knowledge further studies, and in addition to the metal fine particles and the binder resin described above, a small amount of carbon nanotubes are contained in the conductive resin layer, whereby an electrode system and a wiring part exhibiting desired conductivity are obtained. Has been found to be stably formed, and the present invention has been completed.

  The main object of the present invention is to provide a biosensor electrode, a biosensor, and a biosensor conductive resin composition that are inexpensive and have good electrode system and wiring portion conductivity.

  In order to solve the above problems, the present invention provides a biosensor electrode having a support base, and an electrode system and a wiring part formed on the support base, wherein the electrode system and the wiring part are The carbon nanotubes in the conductive resin layer have a conductive resin layer containing metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin formed on the support substrate The biosensor electrode is characterized in that the content of is in the range of 1 mass% or more and 20 mass% or less.

  According to the present invention, since the electrode system and the wiring part have the conductive resin layer having the above-described composition, the electrode system and the wiring part have a good conductivity for the biosensor, which is inexpensive. Can do.

  In the said invention, it is preferable that the conductive material contained in the said conductive resin layer is only the said metal microparticles and the said carbon nanotube.

  In the said invention, it is preferable that the base metal which has the said corrosion resistance is nickel. In the biosensor, an electrode system and a wiring part that can suitably prevent an oxidation-reduction reaction caused by contact with a component in a sample or an electron acceptor (mediator) of the reaction part can be provided.

  The present invention includes a support substrate, an electrode system and a wiring portion formed on the support substrate, a reaction portion disposed on the electrode system, a support substrate, the electrode system and A biosensor having a spacer that forms a sample supply path for supplying a sample to the reaction unit, and a cover disposed on the spacer, wherein the electrode system and the wiring unit are disposed on the support substrate. It has a conductive resin layer that is formed and contains metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin, and the content of the carbon nanotubes in the conductive resin layer is 1 mass. The biosensor is characterized by being in the range of not less than 20% and not more than 20% by mass.

  According to the present invention, since the electrode system and the wiring portion have the conductive resin layer having the above-described composition, the biosensor can be inexpensive and have good conductivity of the electrode system and the wiring portion. .

  In the said invention, it is preferable that the conductive material contained in the said conductive resin layer is only the said metal microparticles and the said carbon nanotube.

  The present invention relates to a biosensor conductive resin composition used for forming a biosensor electrode system and a wiring portion, and includes metal fine particles composed of a base metal having corrosion resistance, a carbon nanotube, a binder resin, and a solvent And the content of the carbon nanotube in the solid content of the biosensor conductive resin composition is in the range of 1% by mass to 20% by mass. A resin composition is provided.

  According to the present invention, since the solid content of the conductive resin composition for a biosensor is the above-described composition, it is possible to manufacture a biosensor that is inexpensive and has good conductivity in the electrode system and the wiring portion. it can. Moreover, since the electrode system and wiring part which have desired electroconductivity can be formed stably, the dispersion | variation in the electroconductivity in each obtained biosensor can be made small.

  In the said invention, it is preferable that the conductive material contained in the said conductive resin composition for biosensors is only the said metal microparticles and the said carbon nanotube.

  According to the present invention, by using the conductive resin layer described above, there is an effect that it is possible to obtain an electrode for a biosensor and the like that are inexpensive and have good conductivity in the electrode system and the wiring portion.

It is the schematic plan view and sectional drawing which show an example of the electrode for biosensors of this invention. It is a disassembled perspective view and sectional drawing which show an example of the biosensor of this invention. It is a schematic plan view which shows an example of the electrode system in the biosensor of this invention. It is the schematic plan view and sectional drawing which show the other example of the electrode for biosensors of this invention. It is a disassembled perspective view which shows the other example of the biosensor of this invention. It is a schematic diagram which shows an example of the usage method of the biosensor of this invention. It is a schematic sectional drawing which shows an example of the conductive resin layer containing metal microparticles and binder resin.

  The biosensor electrode, biosensor, and biosensor conductive resin composition of the present invention will be described below.

A. Biosensor electrode The biosensor electrode of the present invention comprises a support base, and an electrode system and a wiring part formed on the support base, wherein the electrode system and the wiring part are It has a conductive resin layer formed on a support substrate and containing metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin, and contains the carbon nanotubes in the conductive resin layer The amount is in the range of 1% by mass or more and 20% by mass or less.
The “base metal having corrosion resistance” will be described later.

The biosensor electrode of the present invention will be described with reference to the drawings.
FIG. 1 (a) is a schematic plan view showing an example of the biosensor electrode of the present invention, FIG. 1 (b) is a cross-sectional view taken along line AA of FIG. 1 (a), and FIG. It is an enlarged view of the broken line part of FIG.1 (b).
As shown in FIGS. 1A to 1C, the biosensor electrode 1 of the present invention has a support base 2, an electrode system 14 formed on the support base 2, and a wiring portion 15. It is. The electrode system 14 usually has a working electrode 11 and a counter electrode 12. The wiring portion 15 is formed integrally with the electrode system 14. Moreover, the wiring part 15 is normally formed so as to be electrically connected to the terminal part 16.
In the present invention, the electrode system 14 and the wiring portion 15 are formed on the support base material 2 and are electrically conductive containing metal fine particles 3 made of a base metal having corrosion resistance, carbon nanotubes 4, and a binder resin 5. It has the resin layer 6, and content of the carbon nanotube 4 in the conductive resin layer 6 exists in the range of 1 to 20 mass%.

FIG. 2 (a) is an exploded perspective view showing an example of a biosensor provided with the biosensor electrode of the present invention, and FIG. 2 (b) is a cross-sectional view taken along line BB in FIG. 2 (a).
As shown in FIGS. 2A and 2B, the biosensor 100 includes a support base 2, an electrode system 14 and a wiring portion 15 formed on the support base 2, and a working electrode 11 of the electrode system 14. The reaction unit 20 disposed above, the spacer 30 disposed on the support substrate 2 and forming the sample supply path 31 and the air vent channel 32 for supplying a sample to the electrode system 14 and the reaction unit 20, And a cover 40 disposed so as to cover the sample supply path 31.
The spacer 30 is disposed so as to form, for example, a sample supply path 31 and an air vent channel 32 communicating with the sample supply path 31 so that the reaction unit 20 and the counter electrode 12 on the working electrode 11 are exposed.
In this biosensor 100, the sample supply path 31 and the air vent flow path 32 are formed, so that the sample to be measured can be measured using the capillary phenomenon from the sample supply path 31 and the reaction unit 20 and the counter electrode 12 on the working electrode 11. The target component of the sample can be measured.

  According to the present invention, since the electrode system and the wiring part have the conductive resin layer having the above-described composition, the electrode system and the wiring part have a good conductivity for the biosensor, which is inexpensive. Can do.

  More specifically, according to the present invention, the electrode system and the wiring part have a conductive resin layer containing metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin. Thus, the electrode system and the wiring portion can be formed in the biosensor electrode using a printing method. Therefore, compared with the case where it has the metal electrode using the conventional vapor deposition method, the plating method, etc., the electrode for biosensors can be manufactured by a simple method and suppressing the manufacturing cost. Moreover, since no precious metal is used, the biosensor electrode of the present invention can be made inexpensive.

Further, according to the present invention, the conductive resin layer has the above-described composition, so that the conductivity of the electrode system and the wiring portion can be improved. About this reason, it estimates as follows.
FIG. 7 is a schematic cross-sectional view showing an example of a conductive resin layer containing metal fine particles and a binder resin. As shown in FIG. 7, in the conductive resin layer 6 ′ containing the metal fine particles 3 and the binder resin 5 formed on the support substrate 2, the metal fine particles 3 dispersed in the binder resin 5 are in contact with each other. Since there is a portion that does not have electrical conductivity and cannot be conducted, it is assumed that the electrical conductivity cannot be sufficient.
On the other hand, as shown in FIG. 1 (c), in the conductive resin layer 6 in the present invention, the carbon nanotubes 4 are dispersed in the binder resin 5 in addition to the metal fine particles 3, and thus the above-mentioned. Since the carbon nanotubes 4 can be interposed between the metal fine particles 3 that do not have contacts, and both can be conducted, it is assumed that good conductivity can be exhibited.

In addition, in the conductive resin layer containing the metal fine particles and the binder resin described above, in order to increase the contact between the metal fine particles, when the content of the metal fine particles is increased, it is used to form the conductive resin layer. The stability of the conductive resin composition, such as the dispersibility of the fine metal particles in the conductive resin composition (ink), cannot be maintained, and the applicability of the conductive resin composition to the support substrate is reduced. Such a problem may occur.
In addition, in a conductive resin layer containing carbon nanotubes and a binder resin instead of metal fine particles, fine fibrous carbon nanotubes tend to aggregate in the conductive resin composition, and the stability of the conductive resin composition is maintained. A problem that the carbon nanotubes are in contact with and dispersed in the entire conductive resin layer, and that a complicated process is required to form the conductive resin layer as described above. There is a possibility that a problem that it is difficult to form itself may occur. Moreover, since a carbon material is used, there is a possibility that a problem that an electrode for biosensor having stable conductivity cannot be obtained may occur.
In contrast, in the present invention, since the conductive resin layer contains metal fine particles, carbon nanotubes, and a binder resin, the metal fine particles and carbon in the conductive resin composition (conductive resin composition for biosensors). Since the dispersibility of the nanotubes can also be made favorable, it is possible to manufacture an electrode for a biosensor having an electrode system and a wiring portion that stably exhibit desired conductivity. Therefore, it can be set as the electrode for biosensors with favorable productivity.

  Further, according to the present invention, since the metal fine particles are a base metal having corrosion resistance, in the biosensor, the electrode system and the wiring part are components of the biosensor sample, and the electron acceptor (mediator) included in the reaction part. It is also possible to suppress the redox reaction caused by contact with (A).

  Hereinafter, the details of the biosensor electrode of the present invention will be described.

1. Electrode system and wiring part The electrode system and wiring part used in the present invention are formed on a supporting base material, and are formed on the supporting base material, and are formed of fine metal particles composed of a base metal having corrosion resistance. , Carbon nanotubes, and a binder resin, and a conductive resin layer having a carbon nanotube content within a predetermined range.
In the present invention, the electrode system and the wiring portion are usually formed continuously. Further, the wiring part is usually formed so as to be electrically connected to a terminal part described later.

(1) Electrode system The electrode system has at least a working electrode and a counter electrode, and may further have a reference electrode. The working electrode is one electrode for applying a voltage to the reductant electron acceptor. The counter electrode is one electrode for measuring a current flowing by electrons emitted from the electron acceptor to the working electrode. The reference electrode is an electrode serving as a reference when determining the potential of the working electrode. A wiring part is electrically connected to the working electrode, the counter electrode, and the reference electrode, and a terminal part (to be described later) is usually electrically connected to the wiring part. Can be taken out.

  The form of the electrode system is not particularly limited as long as it is a form of a general electrode system in a biosensor. For example, as shown in FIG. 1A and the like, two wiring portions 15 and a terminal portion 16 are formed on the support base 2, the working electrode 11 is connected to one wiring portion 15, and the other wiring portion. 15, a counter electrode 12 may be connected. As shown in FIG. 3A, two wiring portions 15 and a terminal portion 16 are formed on the support base 2, and a working electrode is provided on one wiring portion 15. 11 may be connected, and the counter electrode 12 and the reference electrode 13 may be separately connected to the other wiring portion 15, and as illustrated in FIGS. 3B and 3C, three electrodes are provided on the support base 2. The wiring part 15 and the terminal part 16 may be formed, and the working electrode 11, the counter electrode 12, and the reference electrode 13 may be connected to the three wiring parts 15, respectively.

(2) Wiring part The wiring part in this invention is formed on a support base material. A working electrode, a counter electrode, a reference electrode, and a later-described terminal unit are electrically connected to the wiring unit.
The wiring part is usually formed integrally with the electrode system.

  The form of the wiring part is not particularly limited as long as it is a form of a general wiring part in a biosensor. For example, as shown in FIGS. 1A and 3A to 3C described above. A form is mentioned.

(3) Conductive resin layer The conductive resin layer in the present invention is formed on a supporting substrate and contains metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin. is there. The conductive resin layer functions as an electrode in the electrode system and the wiring part.

  The resistance value of the conductive resin layer is not particularly limited as long as the conductive resin layer functions as an electrode. For example, the measurement conditions include a length of a conductive resin layer having a thickness of 100 μm, a width of 10 mm, and a length of 50 mm. The resistance value when measured from one end of the direction with a tester is preferably 15 MΩ or less, more preferably 10 MΩ or less, and particularly preferably 2 MΩ or less. This is because if the surface resistivity of the conductive resin layer exceeds the above value, it may not function as an electrode.

The surface resistivity of the conductive resin layer is not particularly limited as long as the conductive resin layer functions as an electrode. For example, the surface resistivity is preferably in the range of 10 ⁶ Ω / □ or less. This is because if the surface resistivity of the conductive resin layer exceeds the above value, it may not function as an electrode.

  The volume resistivity of the conductive resin layer is not particularly limited as long as the conductive resin layer functions as an electrode and can be appropriately selected according to the thickness of the conductive resin layer. When the thickness of the conductive resin layer is in the range of 0.1 μm to 200 μm, it is preferably 300 Ωcm or less. When volume resistivity is higher than the said range, there exists a possibility that the electroconductivity as an electrode may not be obtained.

  Here, the resistance value, the surface resistivity, and the volume resistivity are values measured using a resistivity meter Loresta manufactured by Mitsubishi Chemical Corporation.

The conductive resin layer contains fine metal particles made of a base metal having corrosion resistance, carbon nanotubes, and a binder resin.
The conductive resin layer usually contains only metal fine particles and carbon nanotubes as the conductive material.

Here, the conductive material refers to a material that imparts conductivity to the conductive resin layer and a conductive layer described later.
The conductivity of the conductive material means that the volume resistivity is, for example, 10 ⁻¹ Ω · m or less, preferably 10 ⁻³ Ω · m or less, particularly 10 ⁻⁵ Ω · m. m or less is preferable. As a measuring method, for example, a metal film can be measured by JIS K7194 (four probe method). Other materials may be measured by another measuring method or the like.

The metal fine particles used for the conductive resin layer are composed of a base metal having corrosion resistance.
“Corrosion-resistant base metal” is a metal other than gold, silver, platinum, palladium, rhodium, iridium, ruthenium and osmium, and is generally not easily oxidized in the air. A metal having an electrode potential of −1.0 V or more. The “base metal having corrosion resistance” refers to a metal that hardly corrodes when it comes into contact with an electron acceptor (mediator) contained in a reaction part of a biosensor or a component in a sample supplied from the outside. In the present invention, among the “base metals having corrosion resistance”, a metal that is not easily corroded by, for example, chlorine ions is preferable.

Specific examples of the base metal having corrosion resistance include nickel, zinc, copper, cobalt, cadmium and the like.
In the present invention, the base metal having corrosion resistance is preferably nickel. In the biosensor, an electrode system and a wiring part that can suitably prevent an oxidation-reduction reaction caused by contact with a component in a sample or an electron acceptor (mediator) of the reaction part can be provided.

The average particle diameter of the metal fine particles is not particularly limited as long as it can be contained in the conductive resin layer and can exhibit desired conductivity. The average particle size of the metal fine particles is, for example, preferably in the range of 10 nm to 20 μm, more preferably in the range of 50 nm to 10 μm, and particularly preferably in the range of 100 nm to 5 μm. This is because when the average particle size of the metal fine particles is within the above-described range, desired conductivity can be imparted to the conductive resin layer. In addition, as the metal fine particles used in the present invention, it is preferable to use particles having a small average particle size among the numerical ranges described above. The conductive resin layer is usually formed by a printing method using the conductive resin composition containing the above-described metal fine particles, carbon nanotubes, and a binder resin. At this time, if the average particle size of the metal fine particles is large, it cannot be uniformly diffused in the conductive resin composition, making it difficult to stabilize the composition of the conductive resin composition, and the metal fine particles are uniformly dispersed. This is because it may be difficult to form the conductive resin layer.
Further, if the metal fine particles are too large, transfer from the printing plate becomes difficult, and it may be difficult to form a good conductive resin layer.
In addition, the said average particle diameter is the value calculated | required by observing a metal microparticle with an electron microscope, and arithmetic mean.

The content of the metal fine particles in the conductive resin layer is not particularly limited as long as the conductive resin layer can exhibit the desired conductivity, but within the range of 40% by mass to 94% by mass, It is preferably in the range of 60% by mass to 90% by mass, particularly in the range of 70% by mass to 85% by mass. If the content of the metal fine particles is too small, it may be difficult to make the conductive resin layer sufficiently conductive. If the content of the metal fine particles is too large, This is because it may be difficult to form the resin layer or the conductive resin layer may become brittle.
In addition, in this specification, content of each component in a conductive resin layer means the content rate of each component when the whole conductive resin layer is 100 mass%.

  The carbon nanotube used for the conductive resin layer is used for imparting conductivity to the conductive resin layer together with the metal fine particles.

The average diameter (diameter) of the carbon nanotube is not particularly limited as long as desired conductivity can be imparted to the conductive resin layer. For example, the average diameter (diameter) is, for example, in the range of 10 nm to 2000 nm, in particular in the range of 50 nm to 1000 nm. It is preferably within the range of 50 nm to 500 nm.
The average length of the carbon nanotube is not particularly limited as long as desired conductivity can be imparted to the conductive resin layer. For example, the average length of the carbon nanotube is within the range of 0.5 μm to 20 μm, and particularly within the range of 1 μm to 15 μm. In particular, it is preferably in the range of 5 μm to 15 μm.
When the average diameter and the average length of the carbon nanotubes are within the above-described numerical ranges, desired conductivity can be imparted to the conductive resin layer, and the conductive resin layer is preferably formed by a printing method. Because it can.
The average diameter and the average length are values obtained by observing the carbon nanotubes with an electron microscope and calculating the arithmetic average.

  The content of the carbon nanotubes in the conductive resin layer can be appropriately selected according to the application of the biosensor and the like, and is not particularly limited, but is within the range of 1% by mass or more and 20% by mass or less. It is preferably in the range of not less than 15% by mass and not more than 15% by mass, particularly in the range of not less than 2% by mass and not more than 10% by mass. This is because if the carbon nanotube content is less than the above value, it may be difficult to impart desired conductivity to the conductive resin layer. On the other hand, when the content of the carbon nanotubes exceeds the above value, it becomes difficult to stably give desired conductivity to the conductive resin layer, and the conductivity of the obtained biosensor electrode is likely to vary. This is because there is a possibility that the carbon nanotubes may aggregate and be difficult to uniformly disperse in the conductive resin layer.

  Examples of the binder resin used for the conductive resin layer include an acrylic resin, an ester resin, a vinyl chloride resin, a vinyl acetate resin, and an epoxy resin.

  The content of the binder resin in the conductive resin layer is not particularly limited as long as the conductive resin layer can be formed on the support substrate, but is within the range of 5% by mass or more and 50% by mass or less, and 10% by mass. As mentioned above, it is preferable to be in the range of 40% by mass or less, particularly in the range of 15% by mass or more and 30% by mass or less. It is because the conductive resin layer which shows desired electroconductivity can be formed suitably by making content of binder resin into the said range.

  In the conductive resin layer, metal fine particles, carbon nanotubes and binder resin, if necessary, other conductive pigments, reaction reagents such as curing agents and crosslinking agents, and auxiliary agents and additives for improving processability. Etc. may be mixed.

  The thickness of the conductive resin layer is not particularly limited as long as the desired conductivity can be exhibited, but it is in the range of 0.1 μm to 200 μm, in particular in the range of 0.5 μm to 100 μm, in particular 1 μm to 50 μm. It is preferable to be within the range. When the thickness of the conductive resin layer is less than the above range, it is difficult to make the strength of the conductive resin layer of the present invention sufficient, or it is difficult to form the conductive resin layer itself. Because there is a possibility of becoming. Moreover, when the thickness of the conductive resin layer is thicker than the above range, the resistance may increase.

The method for forming the conductive resin layer is not particularly limited as long as it is a method capable of forming a conductive resin layer having an electrode system and a wiring portion pattern on a support substrate. And a method of printing using a conductive resin composition containing metal fine particles, carbon nanotubes, and a binder resin. In order to suppress the occurrence of pinholes, it is preferable to print the conductive resin composition a plurality of times. Examples of the printing method include a gravure printing method, a flexographic printing method, and a screen printing method. Of these, gravure printing and flexographic printing are preferably used. As described above, as the conductive resin layer becomes thicker, the resistance increases. However, these methods can reduce the thickness of the conductive resin layer.
Details of the conductive resin composition will be described in the section “C. Conductive resin composition for biosensor” described later.

  Further, the surface of the conductive resin layer may be mechanically polished or physically etched by a discharge technique such as corona plasma to improve the surface activation.

(4) Terminal part The terminal part in this invention is formed on a support base material. The terminal portion is provided so as to be electrically connected to the wiring portion, and voltage application to the electrode system and extraction of an electric signal can be performed by the terminal portion.

The terminal portion is not particularly limited as long as it can be electrically connected to the wiring portion. For example, as shown in FIG. 1A, the terminal portion 16 may be formed of only the conductive resin layer 6 integrally with the wiring portion 15. For example, as shown in FIGS. 4A and 4B, the terminal portion 16 may be formed of a laminate of the conductive resin layer 6 and the conductive layer 7. In this case, as shown in FIGS. 4A and 4B, the laminated body of the terminal portions 16 may be laminated in the order of the support base 2, the conductive resin layer 6, and the conductive layer 7, which is not illustrated. However, you may laminate | stack in order of a support base material, a conductive layer, and a conductive resin layer. For example, although not shown, the terminal portion may be formed only of a conductive layer. In this case, usually, a part of the conductive resin layer of the wiring portion and the conductive layer are laminated on the supporting base material.
4A is a schematic plan view showing another example of the biosensor electrode of the present invention, and FIG. 4B is a cross-sectional view taken along the line CC of FIG. 4A.

When the terminal portion has a conductive layer, examples of the conductive material used for the conductive layer include gold, platinum, silver, palladium, copper, iron, aluminum, chromium, tin, cobalt, nickel, titanium, cerium, and tantalum. These metals or alloys containing these metals can be used. The conductive layer may contain carbon and a binder resin.
In addition, the conductive layer used for the terminal portion may be a single layer, or two or more layers may be stacked.

  The thickness of the conductive layer varies depending on the type of conductive material, but is preferably in the range of, for example, 0.005 μm to 40 μm, and more preferably in the range of 0.01 μm to 0.1 μm. preferable. If the thickness is less than the above range, the resistance becomes high and the intended electrode may not be obtained. Moreover, it is because there exists a possibility that the crack of a conductive layer, peeling, etc. may arise easily when thickness becomes larger than the said range.

  The method for forming the conductive layer is not particularly limited as long as it is a method capable of forming the conductive layer in a predetermined pattern. For example, a gravure printing method, a flexographic printing method, a screen printing method using a metal paste. , Printing method by inkjet method, physical vapor deposition method such as vacuum deposition method and sputtering method, method of etching metal foil, gravure printing method, flexographic printing method, screen printing method, ink jet containing carbon and binder resin Examples thereof include a method of printing by a method, a laser ablation method and the like. In addition, a water-soluble resist layer is formed in a pattern on a supporting substrate, a conductive layer is formed on the entire surface of the supporting substrate on which the water-soluble resist layer is formed by physical vapor deposition, and the water-soluble resist layer is washed with water. It is also possible to use a method in which the conductive layer on the water-soluble resist layer is removed by dissolving and the conductive layer is patterned.

  The form of the terminal part is not particularly limited as long as it is a form of a general terminal part in a biosensor. For example, FIG. 1 (a), FIG. 3 (a) to (c), and FIG. A form as shown to a) and (b) is mentioned.

2. Support base material The support base material used for this invention supports an electrode system, a wiring part, and a terminal part, and the surface in which an electrode system, a wiring part, and a terminal part are formed has insulation.
Examples of the support base material that can be used include a resin base material, a ceramic base material, a glass base material, a semiconductor base material, a metal base material, and the like whose surfaces are insulated. As the resin substrate, for example, a film of polyethylene terephthalate (PET) resin, vinyl chloride resin, polystyrene (PS) resin, polypropylene (PP) resin, or the like can be suitably used.
The support base material may or may not have flexibility. Moreover, the support base material may have rigidity and may have elasticity.

3. Biosensor Electrode The biosensor electrode of the present invention is used for a biosensor. The details of the biosensor provided with the biosensor electrode of the present invention will be described in the section “B. Biosensor” described later, and thus the description thereof is omitted here.

B. Biosensor The biosensor of the present invention is disposed on a support substrate, an electrode system and a wiring unit formed on the support substrate, a reaction unit disposed on the electrode system, and the support substrate. A spacer that forms a sample supply path for supplying a sample to the electrode system and the reaction unit, and a cover disposed on the spacer, wherein the electrode system and the wiring unit are supported by the support unit. A conductive resin layer formed on a base material and containing a metal fine particle composed of a base metal having corrosion resistance, a carbon nanotube, and a binder resin, and the content of the carbon nanotube in the conductive resin layer Is in the range of 1 mass% or more and 20 mass% or less. That is, the biosensor of the present invention comprises the above-described biosensor electrode.

The biosensor of the present invention will be described with reference to the drawings.
2A is an exploded perspective view showing an example of the biosensor of the present invention, and FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A.
The details of FIGS. 2A and 2B have been described in the section “A. Electrode for Biosensor” described above, and thus description thereof is omitted here.

FIG. 5 is an exploded perspective view showing another example of the biosensor of the present invention.
As shown in FIG. 5, the biosensor 100 of the present invention is disposed on the support base 2, the electrode system 14 and the wiring portion 15 formed on the support base 2, and the working electrode 11 of the electrode system 14. The reaction unit 20, the spacer 30 which is disposed on the support base 2 and forms a sample supply path 31 for supplying a sample to the electrode system 14 and the reaction unit 20, and the sample supply path 31 is covered on the spacer 30. And a cover 40 having an air hole 41.
The spacer 30 is disposed so as to form, for example, a sample supply path 31 that communicates with the air hole 41 of the cover 40 so that the reaction unit 20 and the counter electrode 12 on the working electrode 11 are exposed.
In this biosensor 100, the sample supply path 31 and the air hole 41 are formed, so that the sample to be measured using the capillary phenomenon from the sample supply path 31 is measured on the reaction part 20 and the counter electrode 12 on the working electrode 11. The target component of the sample can be measured.

  According to the present invention, since the electrode system and the wiring portion have the conductive resin layer having the above-described composition, the biosensor can be inexpensive and have good conductivity of the electrode system and the wiring portion. .

Hereinafter, details of the biosensor of the present invention will be described.
The electrode system, wiring section, terminal section, and support base material can be the same as the contents described in the above-mentioned section “A. Electrode for biosensor”, and thus the description thereof is omitted here. .

1. Reaction part The reaction part in this invention is arrange | positioned at the upper part of an electrode system.
In the present invention, the reaction part contains a biological substance, and converts a chemical potential, heat, or optical change accompanying the change movement of the substrate-specific substance into an electrical signal.

The reaction part includes, for example, an enzyme and an electron acceptor as a biological substance.
When measuring the glucose concentration, glucose oxidase (GOD) or glucose dehydrogenase (GDH) can be used as the enzyme. Glucose oxidase and glucose dehydrogenase preferably have high purity, and the species of origin is not particularly limited as long as it has an activity in the range described below. For example, glucose oxidase includes GLO-201 manufactured by Toyobo Co., Ltd. Can be used.
As the electron acceptor, potassium ferricyanide, a ferrocene derivative, a quinone derivative, an osmuum derivative, or the like can be used.

Moreover, when measuring an endotoxin density | concentration, the blood cell component (Limulus Ambozyte Lysate; LAL) of a horseshoe crab can be used for a reaction part. For example, the reaction part may include a factor C, a factor B, a coagulase precursor, and a peptide containing a dye bound thereto. Specifically, examples of the substance containing factor C, factor B and a coagulase precursor include horseshoe crab, amebocyte lysate (a horseshoe crab blood cell extract). Moreover, as the peptide to which the dye is bonded, an oligopeptide having a dye bonded to one end and a peptide protecting group bonded to the other end can be used. Examples of the oligopeptide include X-A-Y (wherein X is a protecting group, Y is a dye, and A is an oligopeptide). Examples of the protecting group X include peptide protecting groups such as t-butoxycarbonyl group (BoC) and benzoyl group. Examples of the dye Y include pNA (p-nitroaniline) and MCA (7-methoxy). Coumarin-4-acetic acid), DNA (2,4-dinitroaniline), Dansyl dye and the like. Oligopeptides should have 2 to 10 amino acids, preferably 2 to 5, more preferably 3 to 4, and examples of tripeptides include Leu-Gly-Arg and Thr-Gly-Arg. it can.
In this case, a sample containing endotoxin is brought into contact with a reaction part containing a peptide to which a factor C, a factor B, a coagulase precursor, and a dye are bound. The factor causes a cascade reaction in which active clotting enzymes are generated one after another from the clotting enzyme precursor and a release reaction of the dye from the peptide by the active clotting enzyme, and is applied to the sample and reaction part after the release reaction. Applying differential pulse voltammetry, endotoxins can be quantified based on the measured current value.
The active clotting enzyme generated by the cascade reaction releases the dye from the peptide to which the dye is bound in the sample and the reaction part. For example, when the peptide to which the dye is bound is Boc-Leu-Gly-Arg-pNA, the dye is pNA.
In addition, about the measuring method of such an endotoxin density | concentration, Unexamined-Japanese-Patent No. 2012-127695 can be referred, for example.

  Biosensors are widely used in reaction systems involving enzymes such as cholesterol sensors, alcohol sensors, scroll sensors, lactate sensors, and fructose sensors as well as glucose sensors and endotoxin sensors by changing the enzyme in the reaction part. be able to. As enzymes used for each biosensor, those suitable for the reaction system such as cholesterol esterase, cholesterol oxidase, alcohol oxidase, lactate oxidase, fructose dehydrogenase, xanthine oxidase, amino acid oxidase and the like can be appropriately used.

The enzyme and electron acceptor are used after appropriately diluted with a solvent. Examples of the solvent include water, alcohol, and a water-alcohol mixed solvent. In addition, the enzyme and the electron acceptor may be uniformly dispersed in a linear or cyclic hydrocarbon poor solvent.
The enzyme and the electron acceptor are preferably in the range of 0.3 unit to 10 unit and the range of 0.5 μg to 200 μg, respectively, per test specimen. The reaction part enzyme and electron acceptor can obtain a reaction amount in accordance with the amount of enzyme (titer / unit), but it may be a small excess of the optimum mass part that ensures the performance of the reaction part.

  Moreover, since the detection part proportional to the area can be obtained, it is preferable to set the reaction part as wide as possible.

The reaction part may contain a hydrophilic polymer or a surfactant. When a hydrophilic polymer is contained, the blood becomes a gel and the response current value is slightly reduced, but the influence on the sensor response of red blood cells and other proteins can be reduced. When a surfactant is contained, the sample can be easily guided to the reaction part even if the sample has a high viscosity.
As the hydrophilic polymer, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, methyl cellulose, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl acetic acid, polyvinyl butyral, or a mixture thereof can be used.
Examples of the surfactant used in the reaction part include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and polyethylene glycols.

The reaction part can be formed by applying a solution containing an enzyme and an electron acceptor on the working electrode of the electrode system and then drying to remove the solvent component.
As a method for applying a solution containing an enzyme and an electron acceptor, for example, a dispenser method can be used.
When forming the reaction part, the enzyme loses its activity when left at a temperature of 40 ° C. or higher for a long time. Therefore, it is preferable to dry the solvent at 40 ° C. or lower and quickly return to room temperature after drying.

  The reaction part may be formed at the upper part of the working electrode. For example, the reaction part may be formed on the working electrode, the reaction part is formed between the spacer and the cover, and is opposed to the working electrode through a space. You may arrange so that.

2. Spacer The spacer in the present invention is disposed on the support substrate and forms a sample supply path for supplying a sample to the electrode system and the reaction part. The spacer is provided in order to form the sample supply path by providing a gap between the support base and the cover in the biosensor.
The spacer is usually disposed on the surface of the support base on the electrode system and on the wiring portion side, and is disposed in a region other than the region in which the sample supply path and the air vent channel formed if necessary are disposed.

The material of the spacer is not particularly limited as long as it can form a spacer having a predetermined thickness. For example, a photocurable resin, a thermosetting resin, an adhesive, or the like can be used. In the case of using a photocurable resin or a thermosetting resin, the spacer can be formed at low cost. When an adhesive is used, the spacer can be formed with high accuracy. A resin base material can also be used as the spacer.
Examples of adhesives include, for example, acrylic adhesives, ester adhesives, vinyl adhesives, silicone adhesives, etc. as synthetic adhesives, starch glues such as glue, natural rubber, and sap as natural adhesives. A polymer or the like can be used. A hot melt adhesive can also be used. Moreover, you may use a double-sided tape as an adhesive agent.

  The thickness of the spacer is preferably in the range of 15 μm or more and 500 μm or less because it is the height of the sample supply path. If the spacer is too thin, sample supply due to capillary action may not be stable. If the spacer is too thick, the sample may not flow uniformly to the reaction part, and the sample may not flow to a part of the reaction part.

The spacer forms a sample supply path. The sample supply channel is a channel provided through the spacer in the horizontal direction, and guides a sample supplied from the outside to the electrode system and the reaction unit.
The width of the sample supply path is preferably in the range of 0.5 mm to 5 mm. If the width of the sample supply path is too narrow, stable sample supply due to capillary action may be difficult, or the area of the reaction part may be reduced and sensitivity may be reduced. Moreover, if the width of the sample supply path is too wide, when the biosensor is manufactured with multiple impositions, when the individual biosensors are cut, the spacer may collapse into an arch shape and the volume in the sample supply path may easily change. There is. The width of the sample supply path may be uniform throughout, or may be wider from the back of the sample supply path toward the inlet.

The spacer may be arranged to further form an air vent channel different from the sample supply channel. The sample supply by capillary action can be promoted.
The air vent channel is arranged to communicate with the sample supply channel. Usually, in the region where the sample supply channel is arranged, the air vent channel is arranged in a region deeper than the electrode system and the reaction part.
The shape of the air vent channel is not particularly limited as long as sample supply by capillary action can be promoted. For example, the sample feed channel and the air vent channel are combined to form a T-shaped channel. Can do. With such a configuration, when a sample is supplied from the outside, an air vent channel through which air in the sample supply channel escapes functions.
The width of the air vent channel can be set within a range of 0.3 mm to 10 mm, for example.

As a method for forming the spacer, any method can be used as long as the spacer can be formed in a predetermined pattern, and the method is appropriately selected according to the material of the spacer. For example, when using a photocurable resin composition, printing methods, such as a gravure printing method and a screen printing method, can be mentioned. Moreover, when using a double-sided tape as an adhesive agent, after forming a sample supply path etc. by punching etc. in a double-sided tape, the method of sticking a double-sided tape on a base material is mentioned. Moreover, when using a resin base material as a spacer, after forming a sample supply path etc. in the resin base material by punching etc., the method of sticking a spacer on a base material through an contact bonding layer is mentioned.
The adhesive used for the adhesive layer can be the same as the adhesive used for the spacer.

3. Cover The cover used in the present invention is disposed on the spacer. Further, the cover is usually disposed on the spacer so as to cover the electrode system and the reaction part and to cover the sample supply path.

As the cover, a base material is usually used. As a base material used for a cover, a resin base material, a ceramic base material, a glass base material, a semiconductor base material, a metal base material etc. can be used, for example. As a resin base material, films, such as a polyethylene terephthalate (PET) resin, a vinyl chloride resin, a polystyrene (PS) resin, a polypropylene (PP) resin, a polyester resin, can be used suitably, for example.
Moreover, the base material may or may not have flexibility.
Moreover, when manufacturing a biosensor by multi-sided attachment, a base material may be long and may be a single wafer.

The substrate may be transparent or opaque, but is preferably transparent. In the case of a transparent substrate, the introduction of the sample can be visually observed when the biosensor is used.
In the case of a transparent substrate, the transmittance in the visible light region is preferably 80% or more. Here, the transmittance can be measured by JIS K7361-1 (a test method for the total light transmittance of a plastic-transparent material).

  The shape of the cover is appropriately selected according to the arrangement of the electrode system, the wiring portion, and the terminal portion in the biosensor. For example, the cover may have a cutout portion so that the terminal portion is exposed. .

The cover may have an air hole 41 that penetrates the cover 40 as illustrated in FIG. Sample supply by capillary action can be promoted in the biosensor.
In the biosensor of the present invention, the air hole is disposed so as to communicate with the sample supply path. Usually, in the region where the sample supply path is arranged, air holes are arranged in a region deeper than the electrode system and the reaction part.
The diameter of the air hole can be set within a range of 0.3 mm to 2 mm, for example.
Examples of the shape of the air hole include a circle, an ellipse, and a polygon.
Examples of the air hole forming method include laser processing, punching processing, and the like.

  The cover arrangement method is appropriately selected according to the configuration of the biosensor. For example, when a double-sided tape is used for the spacer, the support base material on which the electrode system, the wiring portion, and the terminal portion are formed and the cover can be bonded via the spacer. Moreover, when forming a spacer on a support base material using a thermosetting resin or a photocurable resin, the support base material in which the spacer was formed and the cover may be bonded via an adhesive layer. it can.

4). Other Configurations The biosensor of the present invention can be used by appropriately selecting configurations other than those described above as necessary.
An example of such a configuration is an insulating layer.

The insulating layer is formed on the supporting substrate, and is formed so that the electrode system, the reaction part, and the terminal part are exposed and the wiring part is covered. By forming the insulating layer so as to cover the wiring part, it is possible to more suitably prevent the wiring part from being oxidized and to prevent a short circuit.
In addition, a spacer is usually disposed on the insulating layer.

As a material for the insulating layer, for example, a photocurable resin, a thermosetting resin, an adhesive, or the like can be used. In the case of using a photocurable resin or a thermosetting resin, the insulating layer can be formed at a low cost. When an adhesive is used, the insulating layer can be formed with high accuracy.
Note that the adhesive is the same as the adhesive used for the spacer, and thus the description thereof is omitted here.

  The thickness of the insulating layer can be in the range of 3 μm to 50 μm, for example. Especially, it is preferable that the thickness of an insulating layer is thicker than the thickness which combined the electrode system and the reaction part, and the thickness of a wiring part.

As the formation position of the insulating layer, the insulating layer may be formed so as to cover the wiring portion and not to cover the electrode system, the reaction portion, and the terminal portion.
As a method for forming the insulating layer, any method can be used as long as it can form the insulating layer in a predetermined pattern, and the method is appropriately selected according to the material of the insulating layer. For example, when using a photocurable resin composition, printing methods, such as a gravure printing method and a screen printing method, are mentioned, for example. Moreover, when using a double-sided tape as an adhesive agent, after patterning a double-sided tape by stamping etc., the method of sticking a double-sided tape on a base material is mentioned.

5. Biosensor Manufacturing Method Since the biosensor manufacturing method can be the same as a general biosensor manufacturing method, description thereof is omitted here.
In the present invention, the biosensor may be manufactured in multiple faces. In this case, after bonding the support base material on which the electrode system and the wiring portion are formed, the spacer, and the cover, the individual biosensors can be obtained by cutting.

6). Measurement Device FIGS. 6A and 6B are schematic views showing a state where the biosensor of the present invention is connected to the measurement device, FIG. 6A is an overall view, and FIG. 6B is a diagram. It is a figure explaining the inside of the measuring apparatus in the broken-line part of 6 (a).
As illustrated in FIGS. 6A and 6B, the measurement device 200 is a known measurement device, and is a device that connects the biosensor 100 and detects an object to be detected contained in the sample. . The measuring apparatus 200 includes, for example, a connection electrode 203 for receiving an electrical signal generated by the biosensor 100, a calculation unit (not shown), a power source (not shown), a display unit 201, and an operation unit 202. When the biosensor 100 is attached to the attachment portion of the measurement apparatus 200, the two terminal portions 16 of the biosensor 100 are connected to the connection electrodes 203 of the measurement apparatus 200, respectively. With this connection, an electrical signal generated by the biosensor 100 is transmitted to the measuring device 200.

  As a measurement method, for example, a measurer attaches the biosensor 100 to the measurement apparatus 200, introduces a sample from the tip of the biosensor 100 to a sample supply path provided in the spacer, operates the operation unit 202, and performs measurement. To start. When the sample introduced into the sample supply path includes an object to be detected, the object to be detected reacts with a biological substance disposed in the reaction unit, and an electric signal is detected by the electrode system of the biosensor 100. Then, the signal is transmitted from the terminal unit 16 through the electrode system and the wiring unit to the measuring device 200 through the connection electrode 203 of the measuring device 200. The measuring device 200 converts an electrical signal received from the biosensor 100 into a measurement value by a calculation unit. The obtained measurement value is displayed on the display unit 201, and the measurer can visually recognize the measurement result.

C. Conductive resin composition for biosensor The conductive resin composition for biosensor of the present invention is used for forming a biosensor electrode system and wiring portion, and is a metal composed of a base metal having corrosion resistance. It contains fine particles, carbon nanotubes, a binder resin, and a solvent, and the content of the carbon nanotubes in the solid content of the conductive resin composition for biosensors is in the range of 1% by mass to 20% by mass. It is characterized by this.

  According to the present invention, since the solid content of the conductive resin composition for a biosensor is the above-described composition, it is possible to manufacture a biosensor that is inexpensive and has good conductivity in the electrode system and the wiring portion. it can. Moreover, since the electrode system and wiring part which have desired electroconductivity can be formed stably, the dispersion | variation in the electroconductivity in each obtained biosensor can be made small.

  Hereinafter, the detail of the electroconductive composition for biosensors is demonstrated.

1. Components of conductive resin composition for biosensor The conductive resin composition for biosensor of the present invention contains fine metal particles composed of a base metal having corrosion resistance, carbon nanotubes, a binder resin, and a solvent. .

  The details of the metal fine particles, carbon nanotubes, binder resin, and other additives used in the present invention are the same as the contents described in the above-mentioned section “A. Electrode for biosensor”. Description is omitted.

The content of metal fine particles, carbon nanotubes, and binder resin in the solid content of the biosensor conductive resin composition is the same as that in the conductive resin layer described in the section “A. Electrode for biosensor” described above. Since the content of the metal fine particles, the carbon nanotube, and the binder resin can be the same, the description thereof is omitted here.
The content of each component in the solid content of the biosensor conductive resin composition refers to the content ratio of each component when the total solid content of the biosensor conductive resin composition is 100% by mass. Is.

  The solvent used in the present invention is not particularly limited as long as it can be dispersed without altering the above-described solid content. Examples of such solvents include isophorone, butyl carbitol, butyl carbitol acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, nitropropane, mineral spirit, benzene, xylene, toluene, solvent naphtha, and naphthenic series. Solvent, methanol, ethanol, butanol, methyl acetate, ethyl acetate, butyl acetate, octyl acetate, benzyl acetate, cyclohexyl acetate, turpentine oil, dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, Ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, die Glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, dioxane, di-methylene chloride, at least one of trichlorethylene or water used.

The content of the solvent in the biosensor conductive resin composition can be appropriately selected according to the printing method at the time of manufacturing the biosensor. As content of the said solvent, it can be in the range of about 10 mass%-about 85 mass%, for example, Preferably it is 10 mass%-60 mass%.
In addition, content of the solvent in the conductive resin composition for biosensors refers to the content ratio of the solvent when the total mass of the solid content and the solvent is 100% by mass.

2. Conductive resin composition for biosensor The viscosity of the conductive resin composition for biosensor is appropriately selected according to the printing method at the time of producing the biosensor and is not particularly limited. When the conductive resin composition for a biosensor is used, for example, in a screen printing method, the viscosity at 25 ° C. is in the range of 1000 cP to 80000 cP, in particular in the range of 5000 cP to 50000 cP, particularly in the range of 10,000 cP to 40000 cP. Is preferred. When the viscosity of the conductive resin composition for a biosensor is within the above-described range, an electrode system and a wiring portion formed of a conductive resin layer having a good thickness can be formed on a support base material. Because.
The said viscosity shall mean the value in 25 degreeC measured with the small vibration type viscometer (VIBRO VISCOMETER CJV5000, A & D company make).

  About the manufacturing method of the conductive resin composition for biosensors of this invention, since it can be made to be the same as that of the manufacturing method of a general ink, description here is abbreviate | omitted.

  The conductive resin composition for a biosensor of the present invention is used to form an electrode system and a wiring part in the above-described biosensor electrode.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Are included in the technical scope.

  Hereinafter, the present invention will be specifically described using examples and comparative examples.

(Evaluation of conductivity of conductive resin layer)
[Example]
A conductive resin composition was prepared with the following composition. In addition, in the following, the mass% has shown the content rate of each component when the whole solid content in a conductive resin composition is 100 mass%.
<Composition of conductive resin composition>
・ Polyvinyl butyral: 3.0 g (50% by mass)
Nickel particles (average particle size 0.2 μm) ... 2.5 g (42% by mass)
Carbon nanotube (VGCF (registered trademark)) 0.5 g (8% by mass)
・ Ethyl acetate… 27g

  As a support substrate, a polyethylene terephthalate (PET) substrate (Toyobo Ester Film E5100) having a thickness of 25 μm was prepared, and the surface on which the conductive resin composition was applied was subjected to corona treatment. After applying the conductive resin composition described above using a # 6 Miya bar, and drying at 100 ° C. for 5 minutes, three conductive resin layers (measurement samples) each having a thickness of about 100 μm and a size of 10 mm × 50 mm are measured. Produced.

[Comparative Example 1]
Three measurement samples were prepared in the same procedure as in the Examples except that the conductive resin composition was prepared with the following composition.
<Composition of conductive resin composition>
・ Polyvinyl butyral: 3.0 g (50% by mass)
Nickel particles (average particle size 0.2 μm) ... 3.0 g (50% by mass)
・ Ethyl acetate… 27g

[Evaluation]
The resistance value of each measurement sample obtained in Examples and Comparative Examples was measured by the following method. A tester (Digital Multi Tester CDM-2000D Custom) was applied to both ends of a measurement sample having a thickness of about 100 μm, a width of 10 mm, and a length of 50 mm, and the resistance value was confirmed.

  It was confirmed that all of the measurement samples of Examples containing nickel particles and carbon nanotubes as the material exhibiting conductivity exhibited conductivity. On the other hand, it was confirmed that none of the measurement samples of Comparative Examples containing only nickel particles as a material exhibiting conductivity exhibited conductivity.

(Stability of conductive resin composition)
[Example and Comparative Example 2]
Dispersibility of the conductive resin composition of the above-described Examples and the conductive resin composition of Comparative Example 2 having the following composition was confirmed immediately after preparation and after standing for 1 hour after preparation.

<Composition of conductive resin composition of Comparative Example 2>
・ Polyvinyl butyral: 3.0 g (50% by mass)
Nickel particles (average particle size 0.2 μm) 1.7 g (28.3 mass%)
-Carbon nanotube (VGCF (registered trademark)) ... 1.3 g (21.7% by mass)
・ Ethyl acetate… 27g
In addition, in the above, the mass% has shown the content rate of each component when the whole solid content in a conductive resin composition is 100 mass%.

When the conductive resin composition of Example 1 was used, it was possible to form a conductive resin layer by printing on a support substrate in both cases immediately after preparation and after standing for 1 hour. It was.
On the other hand, when the conductive resin composition of Comparative Example 2 was used, it was possible to form a conductive resin layer by printing on a support substrate immediately after preparation, but after standing for 1 hour, Many nickel particles and carbon nanotubes settled in the lower part of the conductive resin composition, and it was difficult to form a film without sufficient stirring.

DESCRIPTION OF SYMBOLS 1 ... Electrode for biosensors 2 ... Support base material 3 ... Metal microparticle 4 ... Carbon nanotube 5 ... Binder resin 6 ... Conductive resin layer 11 ... Working electrode 12 ... Counter electrode 13 ... Reference electrode 14 ... Electrode system 15 ... Wiring part 16 ... Terminal part 20 ... Reaction part 30 ... Spacer 31 ... Sample supply path 32 ... Air vent channel 40 ... Cover 41 ... Air hole 100 ... Biosensor 200 ... Measuring device

Claims (7)

A biosensor electrode comprising a support substrate, and an electrode system and a wiring portion formed on the support substrate,
The electrode system and the wiring portion are formed on the support substrate and have a conductive resin layer containing metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin,
Content of the said carbon nanotube in the said conductive resin layer exists in the range of 1 mass% or more and 20 mass% or less, The electrode for biosensors characterized by the above-mentioned.   2. The biosensor electrode according to claim 1, wherein the conductive material contained in the conductive resin layer is only the metal fine particles and the carbon nanotubes.   The biosensor electrode according to claim 1, wherein the base metal having corrosion resistance is nickel. A support substrate;
An electrode system and a wiring section formed on the support substrate;
A reaction section disposed on the electrode system;
A spacer disposed on the support substrate and forming a sample supply path for supplying a sample to the electrode system and the reaction part;
A cover disposed on the spacer;
A biosensor having
The electrode system and the wiring portion are formed on the support substrate and have a conductive resin layer containing metal fine particles composed of a base metal having corrosion resistance, carbon nanotubes, and a binder resin,
Content of the said carbon nanotube in the said conductive resin layer exists in the range of 1 mass% or more and 20 mass% or less, The biosensor characterized by the above-mentioned.   The biosensor according to claim 4, wherein the conductive material contained in the conductive resin layer is only the metal fine particles and the carbon nanotubes. A conductive resin composition for biosensors used for forming biosensor electrode systems and wiring parts,
Contains fine metal particles composed of base metal with corrosion resistance, carbon nanotubes, binder resin, and solvent,
Content of the said carbon nanotube in solid content of the said conductive resin composition for biosensors exists in the range of 1 mass% or more and 20 mass% or less, The conductive resin composition for biosensors characterized by the above-mentioned.   The conductive resin composition for a biosensor according to claim 6, wherein the conductive material contained in the conductive resin composition for a biosensor is only the metal fine particles and the carbon nanotubes.

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