Sensor and production method of and measurement method using the same

• US 5,720,862 A
• Filed: 04/05/1996
• Issued: 02/24/1998
• Est. Priority Date: 04/07/1995
• Status: Expired due to Term

• Current Assignee: Kyoto Daiichi Kagaku Company Limited
• Original Assignee: Kyoto Daiichi Kagaku Company Limited
• Inventors: Hamamoto, Katsumi, Okuda, Hisashi
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/628,485
• Time in Patent Office: 690 Days
• Field of Search: 204/403, 204/415, 204/418, 435/817, 435/289.1, 205/777.5, 205/778
• US Class Current: 205/777.5
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

There is provided a sensor for the measurement of a content of a material in liquid which material is oxidized with an oxidase enzyme in which sensor a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising the oxidase enzyme and an electron carrier, and the reagent layer further comprises a phosphate.

Claims

1. A sensor for the measurement of a content of a material in liquid which material is oxidized with an oxidase enzyme in which sensor a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, and the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising the oxidase enzyme and an electron carrier wherein the reactive layer further comprises a phosphate.

2. The sensor according to claim 1 wherein the oxidase enzyme is lactic acid oxidase and the sensor is used for the measurement of a lactic acid concentration in the liquid.

3. The sensor according to claim 1 wherein the hydrophilic polymer is purified to at least 99.9% by weight.

4. A sensor for the measurement of a content of a material in liquid which material is oxidized with an oxidase enzyme in which sensor a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, and the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising the oxidase enzyme and an electron carrier wherein the reactive layer further comprises a phosphate, wherein at least one of the hydrophilic polymer layer and the reactive layer further comprises an alkylene oxide polymer.

5. A method for the production of a sensor comprising the steps of:

forming an electrode system composed of a measuring electrode and a counter electrode on an insulating substrate;

coating at least a portion of the electrode system with a hydrophilic polymer layer by applying a solution containing a hydrophilic polymer to the electrode system followed by drying the solution; and

coating at least a portion of the hydrophilic polymer layer with a reactive layer by applying a solution containing a composition for the reactive layer comprising an oxidase enzyme, an electron carrier and a phosphate to the hydrophilic polymer layer followed by drying the solution.

6. The method for the production of the sensor according to claim 5 wherein the oxidase enzyme is lactic acid oxidase and the sensor is used for the measurement of a lactic acid concentration in the liquid.

7. The method for the production of the sensor according to claim 5 wherein the hydrophilic polymer is purified to at least 99.9% by weight.

8. The method for the production of the sensor according to claim 5 wherein the solution containing a composition for the reactive layer includes 0.01 to 1.00% by weight of the phosphate.

9. A method for the production of a sensor comprising the steps of:

forming an electrode system composed of a measuring electrode and a counter electrode on an insulating substrate;

coating at least a portion of the electrode system with a hydrophilic polymer layer by applying a solution containing a hydrophilic polymer to the electrode system followed by drying the solution; and

coating at least a portion of the hydrophilic polymer layer with a reactive layer by applying a solution containing a composition for the reactive layer comprising an oxidase enzyme, an electron carrier and a phosphate to the hydrophilic polymer layer followed by drying the solution, wherein at least one of the solution containing the hydrophilic polymer and the solution containing a composition for the reactive layer includes an alkylene oxide polymer.

10. The method for the production of the sensor according to claim 9 wherein a concentration of the alkylene oxide polymer in the solution is in the range of 0.01 to 1.00% by weight.

11. A method for measuring the concentration of lactic acid in a sample comprising:

contacting a sample with a sensor in which a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising lactic acid oxidase and an electron carrier, and the reactive layer further comprises a phosphate;

obtaining a current value; and

converting the current value into a concentration of the lactic acid in the sample.

12. A sensor for the measurement of a content of a material in liquid which material is oxidized with an oxidase enzyme in which sensor a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, and the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising the oxidase enzyme and an electron carrier wherein the hydrophilic polymer is purified to at least 99.9% by weight.

13. A sensor for the measurement of a content of a material in liquid which material is oxidized with an oxidase enzyme in which sensor a reagent layer is formed on an electrode system composed of a measuring electrode and a counter electrode both of which are formed on an insulating substrate, and the reagent layer is composed of a hydrophilic polymer layer comprising a hydrophilic polymer and a reactive layer comprising the oxidase enzyme and an electron carrier wherein at least one of the hydrophilic polymer layer and the reactive layer further comprises an alkylene oxide polymer.