Method for quantifying specific compound

• US 5,565,085 A
• Filed: 04/25/1995
• Issued: 10/15/1996
• Est. Priority Date: 04/25/1994
• Status: Expired due to Term

• Current Assignee: Panasonic Healthcare Holdings Co., Ltd.
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsutsumi, Haruhiro, Tokuno, Yoshinobu, Ikeda, Shin, Yoshioka, Toshihiko, Nankai, Shiro, Baba, Hideyuki
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/428,040
• Time in Patent Office: 539 Days
• Field of Search: 204/153.12, 204/403, 204/406, 435/817, 435/288, 435/291
• US Class Current: 205/777.5
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

A biosensor for quantifying a specific compound has a reaction layer containing at least an enzyme, and an electrode system having a working electrode and a counter electrode formed on an insulating base plate; the biosensor detects the specific compound contained in a sample on the basis of an electrochemical response. In quantifying, the working electrode and the counter electrode are short-circuited before the voltage is applied therebetween. The short-circuiting eliminates measuring errors that may occur due to nonuniform dissolution of the reaction layer in a sample, and achieves highly reliable quantification of a specific compound.

Claims

1. A method for quantifying a specific compound, which uses a biosensor comprising a reaction layer containing at least an enzyme and an electron acceptor, and an electrode system having a working electrode made of carbon and a counter electrode made of carbon formed on an insulating base plate, and which detects a change in substance concentration caused by a reaction between said enzyme and a specific compound contained in a sample by detecting an electrochemical response obtained when a voltage is applied between said working electrode and said counter electrode, wherein said electrochemical response is an oxidation current of a reduced form of said electron acceptor, and said working electrode and said counter electrode are short-circuited by closing a switch in a circuit connected to terminals of said working electrode and said counter electrode before said voltage is applied therebetween.

2. A method for quantifying a specific compound in accordance with claim 1, wherein alternation of a short circuit state and an open circuit state is repeated a plurality of times before said voltage is applied between said working electrode and said counter electrode.

3. An apparatus for quantifying a specific compound, comprising:

a biosensor including a reaction layer containing at least an enzyme and an electron acceptor, and an electrode system having a working electrode made of carbon and a counter electrode made of carbon formed on an insulating base plate;

means for supplying a sample solution containing a specific compound to said reaction layer of said biosensor;

voltage application means for applying a predetermined voltage between said working electrode and said counter electrode of the biosensor;

means for measuring an oxidation current of a reduced form of said electron acceptor flowing between said working electrode and said counter electrode to which said voltage is applied;

means for short-circuiting said working electrode and said counter electrode by closing a switch in a circuit connected to terminals of said working electrode and said counter electrode before said voltage is applied between said working electrode and said counter electrode.

4. An apparatus for quantifying a specific compound in accordance with claim 3, further comprising means for alternately closing and opening a circuit between said working electrode and said counter electrode a plurality of times.