Biosensor and method of producing the same

• US 20020179441A1
• Filed: 12/18/2001
• Published: 12/05/2002
• Est. Priority Date: 03/08/2000
• Status: Active Grant

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamanishi, Eriko, Miyazaki, Shoji, Terashima, Noriyoshi
• Granted Patent: US 6,860,978 B2
• Time in Patent Office: Days
• US Class Current: 204/403.01
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

In a biosensor comprising a pair of conductive lead parts 2 and 3 formed on an insulating substrate 1, a working electrode 4 and a counter electrode 5 formed at the ends of the conductive lead parts 2 and 3, respectively, and a reaction layer 7 which is formed so as to bridge the both electrodes and reacts with a measurement target substance in a specimen liquid, and measuring the content of the measurement target substance from an electric current value based on the reaction between the measurement target substance and the reaction layer 7, which current value is obtained through the pair of conductive lead parts 2 and 3, the reaction layer 7 which contacts the electrodes 4 and 5 is not provided above at least one of the conductive lead parts 2 and 3 so that the reaction layer 7 and the conductive lead parts 2 and 3 do not contact directly even when pin holes or cracks are generated in the both electrodes.

The biosensor constructed as described above has high reliability and reproduction accuracy, and is able to improve preservation stability.

Claims

1. A biosensor comprising:

a pair of conductive lead parts formed on an insulating substrate;

a working electrode formed at an end of one of the conductive lead parts on the substrate so that a portion of the working electrode overlaps the conductive lead part;

a counter electrode formed at an end of the other conductive lead part on the substrate so that a portion of the counter electrode overlaps the conductive lead part; and

a reaction layer which is formed on the working electrode and the counter electrode so as to bridge the both electrodes and reacts with a measurement target substance in a specimen liquid; and

the biosensor measuring the content of the measurement target substance, from an electric current value based on the reaction between the measurement target substance and the reaction layer, which current value is obtained through the pair of conductive lead parts;

wherein

the reaction layer which contacts the electrodes is not provided above at least one of the conductive lead parts.

2. A biosensor as defined in claim 1, wherein

the conductive lead parts are formed of a metal, and the working electrode and the counter electrode are formed of a material mainly composed of carbon.

3. A biosensor as defined in claim 1, wherein

the reaction layer part is covered with a cover having a specimen supply groove which has an opening at an end and introduces a specimen liquid applied around the opening to the reaction layer, and the conductive lead parts are not located beneath the specimen supply groove.

4. A biosensor as defined in claim 1, wherein

the reaction layer includes at least an enzyme and an electron acceptor.

5. A biosensor manufacturing method comprising:

forming a pair of conductive lead parts on an insulating substrate;

forming a working electrode on the insulating substrate so that a portion of the working electrode is continuous to an end of one of the conductive lead parts, and forming a counter electrode so that a portion of the counter electrode is continuous to an end of the other conductive lead part;

forming an insulating layer so as to cover the portions of the both electrodes, which portions are formed on the conductive lead parts; and

forming a reaction layer which reacts with a measurement target substance in a specimen liquid, on the both electrodes so as to bridge them.

6. A biosensor manufacturing method as defined in claim 5, wherein

the conductive lead parts are formed of a paste mainly composed of a metal, and

the working electrode and the counter electrode are formed of a paste mainly composed of carbon.