Biosensor and method for manufacturing same

• US 20050265897A1
• Filed: 08/08/2003
• Published: 12/01/2005
• Est. Priority Date: 08/13/2002
• Status: Active Grant

• Current Assignee: Gunze Limited
• Original Assignee: Gunze Limited
• Inventors: Deguchi, Tetsuji, Maruo, Masaharu
• Granted Patent: US 7,727,367 B2
• Time in Patent Office: Days
• US Class Current: 422/82.10
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence

Abstract

The present invention provides a biosensor that can be used for easy and quick quantitative analysis of a specific component in a sample with high precision and a method for manufacturing such a biosensor. The present invention also provides a biosensor that can be used for a highly precise quantitative analysis after an extended period of storage, specifically, a biosensor with excellent storage stability, and a method for manufacturing such a biosensor. The present invention relates to a biosensor comprising an electrically insulating substrate (1); an electrode (2) having a working electrode (21) and a counter electrode (22) formed on the substrate; and a reaction part (4) that is adhered to one end of the electrode (2); the reaction part (4) being mainly composed of a hydrophilic polymer comprising an oxidoreductase, an electron acceptor, fine crystalline cellulose powder, and hydrophilic and hydrophobic segments.

Claims

1. A method for manufacturing a biosensor provided with an electrically insulating substrate;

an electrode set having a working electrode and a counter electrode formed on the substrate; and

a reaction part that is adhered to one end of the electrode set, the reaction part comprising an oxidoreductase, an electron acceptor, and fine crystalline cellulose powder;

the method comprising the following sequential steps of (A1) to (C1);

(A1) a step of forming the electrode set by disposing the working electrode and the counter electrode on the electrically insulating substrate in parallel and in close proximity;

(B1) a step of preparing an application liquid for forming the reaction part, by preparing a mixed solution A comprising a good solvent and three components consisting of an oxidoreductase, an electron acceptor, and fine crystalline cellulose, and then adding the mixed solution A to a poor solvent, while stirring, to produce a dispersion liquid B; and

(C1) a step of forming the reaction part by applying the application liquid for forming the reaction part prepared in the step (B1) to one end of the electrode set on the electrically insulating substrate obtained in the step (A1) and drying the application liquid applied on the substrate.

2. A manufacturing method according to claim 1, wherein the electrode is formed of at least one member selected from the group consisting of platinum, gold, palladium, and indium-tin oxides.

3. A biosensor obtainable by a manufacturing method of claim 1.

4. A method for measuring the glucose component, alcohol component, lactic acid component or uric acid component in a sample solution using the biosensor of claim 3.

12. A biosensor obtainable by a manufacturing method of claim 2.

13. A method for measuring the glucose component, alcohol component, lactic acid component or uric acid component in a sample solution using the biosensor of claim 12.

5. A biosensor comprising an electrically insulating substrate;

an electrode set having a working electrode and a counter electrode formed on the substrate; and

a reaction part that is adhered to one end of the electrode set;

the reaction part being mainly composed of an oxidoreductase, an electron acceptor, fine crystalline cellulose powder, and a hydrophilic polymer containing hydrophilic and hydrophobic segments.

6. A biosensor according to claim 5, wherein the hydrophilic polymer is composed of a straight-chain oxyalkylene segment(s) and an alkyl group-branched oxyalkylene segment(s).

7. A biosensor according to claim 6, wherein the average molecular weight of the alkyl group-branched oxyalkylene segment in the hydrophilic polymer is 1500 to 4000, and the content of the straight-chain oxyalkylene segment(s) among all polymer molecules is 30 to 80 wt %.

8. A biosensor according to claim 5, wherein the reaction part is formed by coating a dispersion comprising an oxidoreductase, an electron acceptor, fine crystalline cellulose, and a hydrophilic polymer composed of hydrophilic and hydrophobic segments.

9. A method for manufacturing a biosensor according to claim 8, which comprises the following sequential steps of (A2) to (C2);

(A2) a step of forming the electrode set by disposing the working electrode and the counter electrode in parallel and in close proximity on the electrically insulating substrate;

(B2) a step of preparing an application liquid for forming the reaction part by preparing a mixed solution Ma comprising a good solvent and three components consisting of an oxidoreductase, an electron acceptor, and fine crystalline cellulose, then adding the mixed solution Ma dropwise to a polymer solution Pa containing the hydrophilic polymer dissolved in a solvent that has poor solubility with the three components but good solubility with the hydrophilic polymer, while stirring, to prepare a dispersion; and

(C2) a step of forming the reaction part by applying the application liquid for forming the reaction part prepared in the step (B2) to one end of the electrode set on the electrically insulating substrate obtained in the step (A2) and drying the application liquid applied on the substrate.

14. A biosensor according to claim 6, wherein the reaction part is formed by coating a dispersion comprising an oxidoreductase, an electron acceptor, fine crystalline cellulose, and a hydrophilic polymer composed of hydrophilic and hydrophobic segments.

15. A biosensor according to claim 7, wherein the reaction part is formed by coating a dispersion comprising an oxidoreductase, an electron acceptor, fine crystalline cellulose, and a hydrophilic polymer composed of hydrophilic and hydrophobic segments.

16. A method for manufacturing a biosensor according to claim 14, which comprises the following sequential steps of (A2) to (C2);

(A2) a step of forming the electrode set by disposing the working electrode and the counter electrode in parallel and in close proximity on the electrically insulating substrate;

(B2) a step of preparing an application liquid for forming the reaction part by preparing a mixed solution Ma comprising a good solvent and three components consisting of an oxidoreductase, an electron acceptor, and fine crystalline cellulose, then adding the mixed solution Ma dropwise to a polymer solution Pa containing the hydrophilic polymer dissolved in a solvent that has poor solubility with the three components but good solubility with the hydrophilic polymer, while stirring, to prepare a dispersion; and

(C2) a step of forming the reaction part by applying the application liquid for forming the reaction part prepared in the step (B2) to one end of the electrode set on the electrically insulating substrate obtained in the step (A2) and drying the application liquid applied on the substrate.

17. A method for manufacturing a biosensor according to claim 15, which comprises the following sequential steps of (A2) to (C2);

(A2) a step of forming the electrode set by disposing the working electrode and the counter electrode in parallel and in close proximity on the electrically insulating substrate;

(B2) a step of preparing an application liquid for forming the reaction part by preparing a mixed solution Ma comprising a good solvent and three components consisting of an oxidoreductase, an electron acceptor, and fine crystalline cellulose, then adding the mixed solution Ma dropwise to a polymer solution Pa containing the hydrophilic polymer dissolved in a solvent that has poor solubility with the three components but good solubility with the hydrophilic polymer, while stirring, to prepare a dispersion; and

(C2) a step of forming the reaction part by applying the application liquid for forming the reaction part prepared in the step (B2) to one end of the electrode set on the electrically insulating substrate obtained in the step (A2) and drying the application liquid applied on the substrate.

10. A biosensor comprising:

in its tip portion, an electrically insulating substrate and a cover sheet facing each other with a space in between and a spacer sheet somewhere therebetween; and

a reaction part having an oxidoreductase in a holding space formed by the substrate, the cover sheet and the spacer sheet end;

the liquid sample being delivered from the tip of the sensor into the holding space by capillary action, and an electrochemical change caused by an enzyme reaction between the liquid sample and the reaction part being detected using an electrode set having a working electrode and a counter electrode; and

the biosensor being provided with a projection at only one side of the spacer sheet end in the holding space with the projection extending toward the end of the biosensor.

11. A biosensor according to claim 10, wherein an inside corner part is formed on the spacer sheet end.