JP2001305096A - Biosensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biosensor maintaining constant performance without influencing electrode area when cutting a substrate. SOLUTION: This biosensor for determining substrate in a sample solution has an electroconductive layer formed on the whole surface of an insulating substrate and divided in a plurality of electrodes by first slits. The biosensor is further provided with second slits for dividing the electroconductive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biosensor for quantifying a substrate contained in a sample solution.

[0002]

2. Description of the Related Art A biosensor is a sensor that utilizes a biological material, such as a microorganism, an enzyme, an antibody, or the like, and uses the biological material as a molecular identification element. That is, the reaction that occurs when the immobilized biological material recognizes the target substrate,
It utilizes oxygen consumption, enzymatic reaction, luminescence, etc. due to the respiration of microorganisms.

[0003] Among biosensors, enzyme sensors have been put into practical use. For example, enzyme sensors for glucose, lactose, urea, and amino acids are used in medical measurement and the food industry. The enzyme sensor reduces the electron acceptor by the electrons generated by the reaction between the substrate and the enzyme contained in the sample solution that is the specimen, and the measuring device electrochemically measures the reduction amount of the electron acceptor. Perform quantitative analysis of the sample.

Hereinafter, a conventional biosensor will be described with reference to the drawings. FIG. 5 is a plan view showing a state in which a slit is formed in an electrically conductive layer of a conventional biosensor. FIG. 6 is a perspective view showing a process for producing a conventional biosensor. FIG. 7 is a plan view showing the state of electrodes of a conventional biosensor.

[0005] Reference numeral 101 denotes an insulating substrate made of polyethylene terephthalate or the like. Reference numeral 102 denotes an electrically conductive layer formed on the entire surface of the substrate 101 and made of carbon, a metal substance, or the like. 103a, 103b, 103c, 10
3d is a slit formed in the electrically conductive layer 102. Reference numerals 105, 106, and 107 denote electrodes formed by dividing the electrically conductive layer 102 by the slits 103a, 103b, 103c, and 103d, which are a measurement electrode, a counter electrode, and a detection electrode. Reference numeral 110 denotes a cutting line which is a position where the substrate is cut. 108 is the measuring electrode 10
5, a spacer covering the counter electrode 106 and the detection electrode 107; Reference numeral 109 denotes a rectangular notch provided in the center of the front edge of the spacer 108 and forming a sample supply path. 11
Reference numeral 1 denotes a measurement electrode 105, a counter electrode 106, and a detection electrode 1.
Reference numeral 112 denotes a reagent layer formed by applying a reagent containing an enzyme to 07, and 112 is a cover that covers the spacer 108. Reference numeral 113 denotes an air hole provided at the center of the cover 112. In addition, the sensor wafer X has an electrically conductive layer 102 formed on a substrate 101, and the electrically conductive layer 102 is divided by slits 103a, 103b, 103c, and 103d. Reference numeral 106 denotes a substrate on which a detection electrode 107 is formed. Further, each wafer Y is a sensor wafer X,
This is the state for each biosensor.

A conventional biosensor will be described with reference to the drawings in the order of manufacturing steps. First, the electrically conductive layer 102 is formed over the entire surface of the belt-shaped substrate 101 by a sputtering method for forming a thin film.

Next, as shown in FIG. 5, a slit 103a is formed by using a laser in a region where each individual wafer Y of the electrically conductive layer 102 formed on the substrate 101 is formed.
103b, 103c and 103d are formed, and the measuring electrode 10
5. The electroconductive layer 102 is divided into the counter electrode 106 and the detection electrode 107, and a plurality of biosensor electrodes are arranged side by side to form a sensor wafer X.

Next, as shown in FIG.
In the case of a blood glucose level sensor, a reagent composed of glucose oxidase as an enzyme and potassium ferricyanide as an electron acceptor is applied to form a reagent layer 111. Next, a spacer 108 having a notch 109 for forming a sample supply path is provided on the measurement electrode 105, the counter electrode 106, and the detection electrode 107, and a cover 112 is provided thereon.
Is installed. Here, one end of the notch 109 of the spacer 108 communicates with an air hole 113 provided in the cover 112.

Next, the plurality of biosensors produced in the above-described steps are cut along the cutting line 110 to produce individual biosensors. In order to measure the sample, when a sample liquid such as blood is supplied to the sample supply path formed by the spacer 108, a certain amount of the sample is sucked into the sample supply path by the capillary action by the air hole 113, It reaches above the electrode 106, the measurement electrode 105, and the detection electrode 107. The reagent layer 111 formed on the electrode is dissolved by the blood, for example, an oxidation-reduction reaction occurs between the reagent and the sample, and the measurement electrode 1
An electrical change occurs between the electrode 05 and the counter electrode 106. At the same time, if the sample is correctly filled in the sample supply path, an electrical change occurs between the measurement electrode 105 and the detection electrode 107. By sensing this, the measurement electrode 105 and the counter electrode 10
When a voltage is applied to 6, for example, in the case of a blood glucose level sensor,
A current proportional to the glucose concentration is generated, and the blood sugar level can be measured from the value.

[0010]

However, in the conventional biosensor, when the plurality of biosensors are cut into individual biosensors, the biosensors may not be cut along the cutting line 110 and may be shifted from the cutting line 110. is there. FIG. 7A is a diagram showing a state of the electrode when the cutting is performed correctly. FIG. 7B is a diagram illustrating a state of the electrode when the cutting position is shifted to the left from the cutting line 110. FIG. 7C is a diagram illustrating the state of the electrode when the cutting position is shifted to the right from the cutting line 110. Individual wafer Y
Electrode 105 and counter electrode 106 depending on the cutting position of
Is determined, if the cutting position deviates from the cutting line 110, the area of the measurement electrode 105 and the counter electrode 106 changes, and the resistance of each electrode changes.
Therefore, there is a problem that the value of the current flowing through the electrode changes, and the accuracy of the biosensor varies.

The present invention has been made in view of the above problems, and has as its object to provide a biosensor capable of maintaining a constant performance without affecting the area of an electrode when cutting a substrate.

[0012]

According to a first aspect of the present invention, there is provided a biosensor in which an electrically conductive layer formed on an entire surface of an insulating substrate is divided by a first slit. A biosensor for quantifying a substrate contained in the sample solution, comprising a plurality of electrodes and a reagent layer made of a reagent reacted with the sample solution, wherein the electrode is formed by dividing the electrically conductive layer. The second slit that defines the area of
It is characterized by being provided.

Further, the biosensor according to claim 2 is
2. The biosensor according to claim 1, wherein the shape of the substrate is substantially rectangular, and one or two or more second slits are provided in parallel with any one side of the substantially rectangular shape. I do.

[0014] The biosensor according to claim 3 is
3. The biosensor according to claim 1, wherein the spacer has a notch forming a specimen supply path for supplying the sample liquid to the electrode, and communicates with the specimen supply path disposed on the spacer. 4. And a cover having an air hole.

Further, the biosensor according to claim 4 is
The biosensor according to any one of claims 1 to 3, wherein the electrically conductive layer is formed on the insulating substrate by a sputtering method.

Further, the biosensor according to claim 5 is
The biosensor according to any one of claims 1 to 4, wherein the first slit and the second slit are formed by processing the electrically conductive layer 2 with a laser. And

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 The biosensor according to the first embodiment will be described with reference to the drawings. FIG.
FIG. 3 is a plan view showing a state where a slit is formed in the electrically conductive layer of the biosensor according to the first embodiment. FIG.
FIG. 3 is a diagram showing individual wafers of the biosensor according to the first embodiment. FIG. 3 is a perspective view illustrating a process of manufacturing the biosensor according to the first embodiment. FIG.
FIG. 2 is a plan view showing the state of the electrodes of the biosensor according to the first embodiment.

Reference numeral 1 denotes an insulating substrate made of polyethylene terephthalate or the like. Reference numeral 2 denotes an electric conductive layer formed on the entire surface of the substrate 1 and made of an electric conductive substance such as a noble metal such as gold or palladium or carbon. 3a, 3
b, 3c, and 3d are first slits provided in the electrically conductive layer 2. Reference numerals 5, 6, and 7 denote electrodes formed by dividing the electrically conductive layer 2 by the first slits 3a, 3b, 3c, and 3d, and the measurement electrode, the counter electrode, and the sample are reliably inserted into the sample supply. This is a detection electrode which is an electrode for confirming whether or not suction has been performed. Reference numeral 10 denotes a cutting line which is a position for cutting the substrate. 4a and 4b are second slits for defining the area of the electrode. Reference numeral 8 denotes a spacer that covers the measurement electrode 5, the counter electrode 6, and the detection electrode 7. Reference numeral 9 denotes a rectangular notch formed in the center of the front edge of the spacer 8 and forming a sample supply path. Reference numeral 11 denotes a reagent layer formed by applying a reagent containing an enzyme to the measurement electrode 5, the counter electrode 6, and the detection electrode 7. 12 is a cover for covering the spacer 8. Reference numeral 13 denotes an air hole provided at the center of the cover 12. In addition, the sensor wafer R includes an electric conductive layer 2 formed on a substrate 1 and a first slit 3a, 3b, 3c, 3d and a second slit 4 formed on the electric conductive layer 2.
The substrate is divided by a and 4b, and a measurement electrode 5, a counter electrode 6, and a detection electrode 7, which are electrodes of a plurality of biosensors, are formed on the substrate. Further, each wafer S is a sensor wafer R
Is a state for each biosensor.

The biosensor according to the first embodiment will be described in the order of manufacturing steps. First, the electrically conductive layer 2 is formed on the entire surface of the belt-like substrate 1 by a sputtering method using a noble metal thin film such as gold or palladium. Next, as shown in FIG. 1, a first slit 3a, 3b, 3c, 3d is formed by using a laser in a region where each individual wafer S of the electrically conductive layer 2 formed on the substrate 1 is formed. Is formed, and the electrically conductive layer 2 is divided into the measurement electrode 5, the counter electrode 6, and the detection electrode 7. Further, a second slit 4a is provided on the right side of the first slit 3a, and a second slit 4b is provided on the left side of the first slit 3b. A laser is used to form a plurality of individual wafers S at positions where the area between the substrate and the counter electrode 6 has a predetermined area. FIG. 2A shows a plan view of each wafer S. FIG. 2B shows a front view of each wafer S.

The first slits 3a, 3b, 3c,
The substrate 1 is formed on the substrate 1 by a screen printing method or a sputtering method using a printing plate or a masking plate on which a pattern necessary for forming the electrically conductive layer 2 having 3d and the second slits 4a and 4b is arranged in advance. The first slits 3a, 3b, 3c, 3d and the second slits 4a, 4b may be formed by providing the electrically conductive layer 2.

The first slits 3a, 3b, 3c,
3d and the second slits 4a, 4b
As a method for providing the conductive layer 2, a part of the electrically conductive layer 2 may be shaved with a jig having a sharp tip or the like.

Next, as shown in FIG. 3, in the case of a blood glucose level sensor, a reagent comprising glucose oxidase as an enzyme and potassium ferricyanide as an electron acceptor is placed on each wafer S as a measuring electrode 5 as an electrode. , Counter electrode 6,
The reagent layer 11 is formed by coating on the detection electrode 7.

Next, a notch 9 for forming a sample supply path on the measurement electrode 5, the counter electrode 6, and the detection electrode 7 is provided.
Is installed. Next, the cover 12 is set on the spacer 8. Here, one end of the notch 9 of the spacer 8 communicates with an air hole 13 provided in the cover 12.

After the spacers 8 are formed on the electrodes of the measuring electrode 5, the counter electrode 6 and the detecting electrode 7, the reagent exposed in the notch 9 of the measuring electrode 5, the counter electrode 6 and the detecting electrode 7 May be applied to form the reagent layer 11.

Next, the plurality of biosensors produced in the above-described steps are cut along the cutting line 10 to produce individual biosensors. Here, the state of the electrode when the cutting position is shifted to the left from the cutting line 10 is shown in FIG. 4A, and the state of the electrode when the cutting position is shifted to the right from the cutting line 10 is shown in FIG.
Is shown in Regardless of whether it is shifted to the right or left, the areas of the measurement electrode 5 and the counter electrode 6 are already defined by the first slit and the second slit, so that the As long as cutting is performed between the slits 4a and 4b, the area of the measuring electrode 5 and the counter electrode 6 becomes as shown in FIG.
Is the same as the area of the electrode when it is cut.

In the measurement of the sample, the measuring electrode 5
The second slit 4b does not need to be provided, and only the second slit 4a that defines the area of the measurement electrode 5 may be used because the area greatly depends on the area and the reaction.

In order to measure a sample, blood is supplied as a sample liquid as a sample to the sample supply path formed by the cutout portion 9 of the spacer 8. It is sucked inside and reaches above the counter electrode 6, the measurement electrode 5, and the detection electrode 7. The reagent layer 11 formed on the electrode is dissolved by the blood sample, and an oxidation-reduction reaction occurs between the reagent and a specific component in the sample. Here, if the sample is correctly filled in the sample supply path, an electrical change occurs between the counter electrode 6 and the detection electrode 7. Thus, it is confirmed that the sample has been sucked up to the detection electrode 7. Since an electrical change also occurs between the measurement electrode 5 and the detection electrode 7, it may be confirmed that the sample has been sucked up to the detection electrode 7. After promoting the reaction between the sample and the reagent for a certain period of time after the sample is aspirated to the detection electrode 7, a certain voltage is applied to the measurement electrode 5 and the counter electrode 6 or both the counter electrode 6 and the detection electrode 7. I do. Since it is a blood glucose level sensor, a current proportional to the glucose concentration is generated, and the blood glucose level can be measured from the value.

Although the blood glucose sensor has been described in the first embodiment, it can be used as a biosensor other than the blood glucose sensor by changing the components and the sample of the reagent layer 11. Although the biosensor having three electrodes has been described in the first embodiment, the area of the electrode may be defined by the second slit even when the number of electrodes is other than that.

Further, at least the area of the measurement electrode which greatly affects the measurement accuracy may be defined by the second slit. The position of the second slit is not limited to this position as long as the area of the electrode can be defined. Further, the shape of the biosensor may be other than the shape of the biosensor according to the first embodiment, as long as the area of the electrode can be defined by the second slit.

As described above, in the biosensor according to the first embodiment, since the area of each electrode is defined by the two second slits parallel to the long side of the biosensor, The area of the electrode is defined by the second slit, and there is an effect that the area of each electrode does not change depending on the cutting position and the accuracy does not vary. A reagent layer formed of a reagent that reacts with a sample liquid; a spacer having a cutout that forms a sample supply path for supplying the sample liquid to the electrode; and a sample supply path disposed on the spacer. And a cover having an air hole which communicates with the sample supply passage, so that the sample liquid can be easily sucked into the sample supply path. Since the electric conductive layer is formed on the entire surface of the insulator substrate by a sputtering method and is divided into a plurality of electrodes by the first slit, a highly accurate electrode can be created.
This has the effect of increasing measurement accuracy. In addition, since the first slit and the second slit are formed by laser, high-precision processing can be performed, the area of each electrode can be defined with high accuracy, and the interval between each electrode can be reduced. Therefore, the size of the biosensor can be reduced.

[0031]

As described above, according to the first aspect of the present invention,
According to the biosensor described in (1), the biosensor has a plurality of electrodes formed by dividing the electrically conductive layer formed on the entire surface of the insulating substrate by the first slit, and a reagent layer made of a reagent that reacts with the sample liquid. Then, in the biosensor for quantifying the substrate contained in the sample liquid, since the second slit that defines the area of the electrode by dividing the electrically conductive layer, is provided. When the substrate is cut, the area of each electrode is defined in advance by the second slit, so that the area of each electrode does not change depending on the cutting position, and there is no variation in accuracy. Have.

According to the biosensor of the second aspect of the present invention, in the biosensor of the first aspect, the shape of the substrate is substantially rectangular, and the second slit is formed in the substantially rectangular shape. Since one or two or more are provided in parallel to any one side of the above, the area of each electrode can be easily defined by the second slit,
When the substrate is cut, the area of each electrode does not change due to the shift of the cutting position, and there is an effect that the accuracy does not vary.

According to a third aspect of the present invention, there is provided the biosensor according to the first or second aspect, wherein the notch forming a sample supply path for supplying the sample liquid to the electrode is provided. And a cover disposed on the spacer and having an air hole communicating with the sample supply path, so that the sample liquid can be easily sucked into the sample supply path. There is an effect that there is.

According to a fourth aspect of the present invention, in the biosensor according to any one of the first to third aspects, the electric conductive layer is formed by sputtering on the insulating substrate. Since it is formed by the method, a highly accurate thin film can be formed, a high-precision electrode can be formed, and the accuracy of measurement can be improved.

According to the biosensor according to the fifth aspect of the present invention, in the biosensor according to any one of the first to fourth aspects, the first slit and the second slit are electrically connected. Since the conductive layer 2 is formed by processing with a laser, the processing can be performed with high accuracy, and the area of each electrode can be defined with high accuracy. In addition, since the distance between the electrodes can be reduced, the size of the biosensor can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state where a slit is formed in an electrically conductive layer of a biosensor according to a first embodiment.

FIG. 2 is a diagram showing individual wafers of the biosensor according to the first embodiment.

FIG. 3 is a perspective view showing a process of producing the biosensor according to the first embodiment.

FIG. 4 is a plan view showing the state of the electrodes of the biosensor according to the first embodiment.

FIG. 5 is a plan view showing a state in which a slit is formed in an electrically conductive layer of a conventional biosensor.

FIG. 6 is a perspective view showing a process for producing a conventional biosensor.

FIG. 7 is a plan view showing a state of an electrode of a conventional biosensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Electric conductive layer 3a 1st slit 3b 1st slit 3c 1st slit 3d 1st slit 4a 2nd slit 4b 2nd slit 5 Measurement electrode 6 Counter electrode 7 Detecting electrode 8 Spacer 9 Notch Part 10 Cutting line 11 Reagent layer 12 Cover 13 Air hole R Sensor wafer S Individual wafer 101 Substrate 102 Electric conductive layer 103a Slit 103b Slit 103c Slit 103d Slit 105 Measurement electrode 106 Counter electrode 107 Detection electrode 108 Spacer 109 Notch 110 Cutting Line 111 Reagent layer 112 Cover 113 Air hole X Sensor wafer Y Individual wafer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C12Q 1/54 G01N 27/30 353J 353R (72) Inventor Hiroyuki Tokunaga 8-1, Koshinmachi, Takamatsu City, Kagawa Prefecture Matsushita Kotobuki Electronics Co., Ltd. F-term (reference) 4B029 AA07 BB16 CC03 CC08 FA12 4B063 QA01 QA18 QA19 QQ02 QQ68 QR03 QR83 QS07 QS28 QS36 QS39 QX05

Claims (5)

[Claims] A plurality of electrodes formed by dividing an electrically conductive layer formed on the entire surface of an insulating substrate by a first slit;
A biosensor for quantifying a substrate contained in the sample solution, the reagent layer comprising a reagent to be reacted with the sample solution, wherein the electroconductive layer is divided to define an area of the electrode A biosensor comprising a second slit. 2. The biosensor according to claim 1, wherein the shape of the substrate is substantially rectangular, and one or two or more second slits are provided in parallel with any one side of the substantially rectangular shape. A biosensor characterized by: 3. The biosensor according to claim 1, wherein the spacer has a notch forming a specimen supply path for supplying the sample liquid to the electrode, and the spacer is disposed on the spacer. A cover having an air hole communicating with the sample supply path. 4. The biosensor according to claim 1, wherein the electrically conductive layer is formed on the insulating substrate by a sputtering method. Sensor. 5. The biosensor according to claim 1, wherein the first slit and the second slit are formed by processing the electric conductive layer with a laser. A biosensor, characterized in that: