Biosensor, biosensor chip and biosensor device

• US 9,074,999 B2
• Filed: 10/08/2014
• Issued: 07/07/2015
• Est. Priority Date: 07/02/2002
• Status: Expired due to Fees

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Healthcare Holdings Co., Ltd.
• Inventors: Ueno, Hiroya, Nakatsuka, Junji
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US14/509,728
• Publication Number:
  US 20150053557A1
• Time in Patent Office: 272 Days
• US Class Current: 1/1
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: G01N 27/30 Electrodes, e.g. test electrodes; Half-cells G01N27/414 takes precedence
• CPC Class Codes: G01N 27/307 Disposable laminated or multilayered electrodes G01N27/3272 takes precedence
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• CPC Class Codes: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875
• CPC Class Codes: G01N 27/416 Systems G01N27/27 takes precedence
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence

Abstract

A biosensor includes a working electrode 101, a counter electrode 102 opposing the working electrode 101, a working electrode terminal 103 and a working electrode reference terminal 10 connected to the working electrode 101 by wires, and a counter electrode terminal 104 connected to the counter electrode 102 by a wire. By employing a structure with at least three electrodes, it is possible to assay a target substance without being influenced by the line resistance on the working electrode side.

Claims

1. A biosensor device, comprising:

a biosensor, comprising;

a working electrode;

a counter electrode;

a working electrode terminal;

a counter electrode terminal; and

a reference terminal;

the working electrode being connected to the working electrode terminal; and

the counter electrode being connected to the counter electrode terminal and to the reference terminal; and

a measurement circuit configured to be connected to the biosensor for performing an assay of a fluid to determine the concentration of a substance in the fluid, the measurement circuit comprising;

a first voltage application section coupled to the working electrode terminal; and

a second voltage application section coupled to the counter electrode terminal and to the reference terminal;

wherein the second voltage application section uses a voltage at the reference terminal to control a voltage applied to the counter electrode terminal.

2. The biosensor device of claim 1, wherein the first voltage application section outputs a signal representative of the level of a current flowing through the working electrode terminal.

3. The biosensor device of claim 1, wherein:

the connection between the counter electrode and the counter electrode terminal has a resistance; and

the second voltage application section controls the voltage applied to the counter electrode terminal so that a voltage drop caused by the resistance is compensated.

4. The biosensor device of claim 1, wherein substantially no current flows through the reference terminal during the assay.

5. The biosensor device of claim 1, wherein the second voltage application section comprises a first amplifier having an output coupled to the counter electrode terminal and an input.

6. The biosensor device of claim 5, wherein the second voltage application section further comprises a second amplifier having an output coupled to the input of the first amplifier and an input coupled to the reference terminal.

7. The biosensor device of claim 1, wherein the second voltage application section comprises an amplifier having an input coupled to the reference terminal and an output coupled to the counter electrode terminal.

8. A device configured to be connected to a biosensor for assaying a concentration of a substance in an assayed fluid based on a current flowing between a working electrode and a counter electrode of the biosensor, the device comprising:

a first terminal configured to be connected to the working electrode of the biosensor, and a second terminal and a third terminal that are configured to be connected to the counter electrode of the biosensor,

a first voltage application section coupled to the first terminal; and

a second voltage application section coupled to the second terminal and to the third terminal;

wherein;

substantially no current flows through the third terminal during the assay; and

the second voltage application section uses a voltage at the third terminal to control a voltage applied to the second terminal.

9. The device of claim 8, wherein the first voltage application section outputs a signal representative of the level of a current flowing through the first terminal.

10. The device of claim 8, wherein

the connection between the counter electrode and the second terminal has a resistance;

and

the second voltage application section controls the voltage applied to the second terminal so that a voltage drop caused by the resistance is compensated.

11. The device of claim 8, wherein the second voltage application section comprises a first amplifier having an output coupled to the second terminal and an input.

12. The device of claim 11, wherein the second voltage application section further comprises a second amplifier having an output coupled to the input of the first amplifier and an input coupled to the third terminal.

13. The device of claim 8, wherein the second voltage application section comprises an amplifier having an input coupled to the third terminal and an output coupled to the second terminal.

14. A method for assaying a concentration of a substance in an assayed fluid based on a current flowing between a working electrode and a counter electrode of a biosensor, the biosensor having a working electrode terminal connected to the working electrode, and a counter electrode terminal and a reference terminal that are connected to the counter electrode, the method comprising the steps of:

connecting the biosensor to a measurement circuit having a first voltage application section and a second voltage application section;

applying a voltage from the first voltage application section to the working electrode terminal;

applying a voltage from the second voltage application section to the counter electrode terminal;

using a voltage at the reference terminal to control the voltage applied to the counter electrode terminal by the second voltage application section; and

detecting a current flowing through the working electrode terminal.

15. The method of claim 14, further comprising the step of outputting from the first voltage application section a signal representative of the level of the current detected in the detecting step.

16. The method of claim 14, wherein the step of applying a voltage from the second application section comprises the step of the second voltage application section applying the voltage to the counter electrode terminal to compensate for a voltage drop caused by a resistance in the connection between the counter electrode and the counter electrode terminal.

17. The method of claim 14, wherein substantially no current flows at the reference terminal during the assay.