Biosensor, biosensor chip, and biosensor device

• US 20040251131A1
• Filed: 03/02/2004
• Published: 12/16/2004
• Est. Priority Date: 07/02/2002
• Status: Active Grant

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nakatsuka, Junji, Ueno, Hiroya
• Granted Patent: US 7,540,947 B2
• Time in Patent Office: Days
• US Class Current: 204/403.01
• 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, comprising:

a working electrode to be in contact with an assayed fluid during an assay;

a counter electrode to be in contact with the assayed fluid during an assay, the counter electrode opposing the working electrode with an interval therebetween for allowing a flow of the assayed fluid;

a working electrode terminal connected to the working electrode;

a counter electrode terminal connected to the counter electrode; and

a reference terminal connected to one or both of the working electrode and the counter electrode, through which substantially no current flows during an assay.

2. The biosensor of claim 1, wherein a biological substance or a microorganism that changes a state of a substance contained in the assayed fluid is immobilized on at least one of the working electrode and the counter electrode.

3. The biosensor of claim 1, wherein the reference terminal is connected to only one of the working electrode and the counter electrode.

4. The biosensor of claim 3, further comprising:

a first line connecting the working electrode to the working electrode terminal;

a second line connecting the working electrode or the counter electrode to the reference terminal; and

a third line connecting the counter electrode to the counter electrode terminal.

5. The biosensor of claim 1, wherein the reference terminal includes:

a working electrode reference terminal connected to the working electrode; and

a counter electrode reference terminal connected to the counter electrode.

6. The biosensor of claim 5, further comprising:

a fourth line connecting the working electrode to the working electrode terminal;

a fifth line connecting the working electrode to the working electrode reference terminal;

a sixth line connecting the counter electrode to the counter electrode reference terminal; and

a seventh line connecting the counter electrode to the counter electrode terminal,

wherein at least two of the fourth line, the fifth line, the sixth line and the seventh line are provided in different wiring layers so as to at least partially overlap each other as viewed from above.

7. The biosensor of claim 4, wherein the first line and the second line are provided in different wiring layers.

8. The biosensor of claim 4, wherein the second line and the third line are provided in different wiring layers.

9. The biosensor of claim 4, wherein:

the working electrode, the counter electrode, the reference terminal, the working electrode terminal, the counter electrode terminal, the first line, the second line and the third line are provided on a substrate; and

one of the working electrode terminal and the counter electrode terminal is provided on a reverse surface of the substrate.

10. The biosensor of claim 4, wherein the working electrode terminal and the counter electrode terminal are provided in different wiring layers.

11. The biosensor of claim 10, wherein the third line is provided so as to extend across a plurality of wiring layers.

12. The biosensor of claim 10, wherein:

the counter electrode has a generally-circular shape; and

a portion of an inner periphery of the working electrode is circular with a substantially constant distance from the counter electrode.

13. The biosensor of claim 10, wherein:

the working electrode has a generally-circular shape; and

a portion of an inner periphery of the counter electrode is circular with a substantially constant distance from the working electrode.

14. The biosensor of claim 4 or 5, wherein:

a plurality of the working electrodes are provided; and

the counter electrodes, each opposing one of the working electrodes, are integrated together.

15. The biosensor of claim 5, wherein:

a plurality of the counter electrodes are provided; and

the working electrodes, each opposing one of the working electrodes, are integrated together.

16. The biosensor of claim 4, wherein a cross-sectional area of the third line is greater than that of the first line.

17. A biosensor chip, comprising:

a biosensor including;

a working electrode to be in contact with an assayed fluid during an assay;

a counter electrode to be in contact with the assayed fluid during an assay, the counter electrode opposing the working electrode with an interval therebetween for allowing a flow of the assayed fluid;

a sensor section for holding the assayed fluid;

a working electrode terminal connected to the working electrode;

a counter electrode terminal connected to the counter electrode; and

a reference terminal connected to one or both of the working electrode and the counter electrode, through which substantially no current flows during an assay, the biosensor being provided on a substrate; and

a measurement circuit connected to the biosensor and provided on a substrate.

18. The biosensor chip of claim 17, wherein a biological substance or a microorganism that changes a state of a substance contained in the assayed fluid is immobilized on at least one of the working electrode and the counter electrode.

19. The biosensor chip of claim 17, wherein the reference terminal is connected to only one of the working electrode and the counter electrode.

20. The biosensor chip of claim 19, wherein:

the reference terminal is connected to the working electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal and having an ammeter;

a working electrode potential reference circuit connected to the reference terminal;

a counter electrode voltage application section connected to the counter electrode terminal;

a base voltage source for supplying a base voltage to each of the working electrode potential reference circuit and the counter electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal during an assay.

21. The biosensor chip of claim 20, wherein the working electrode potential reference circuit generates a signal so that a voltage applied to the reference terminal is substantially equal to the base voltage supplied to the working electrode potential reference circuit during an assay.

22. The biosensor chip of claim 19, wherein:

the reference terminal is connected to the counter electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal;

a counter electrode voltage application section connected to the counter electrode terminal and having an ammeter;

a counter potential reference circuit connected to the reference terminal;

a base voltage source for supplying a base voltage to each of the counter electrode potential reference circuit and the working electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal during an assay.

23. The biosensor chip of claim 22, wherein the counter electrode potential reference circuit generates a signal so that a voltage applied to the reference terminal is substantially equal to the base voltage supplied to the counter electrode potential reference circuit during an assay.

24. The biosensor chip of claim 19, wherein:

the reference terminal is connected to the working electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal and the reference terminal and having an ammeter;

a counter electrode voltage application section connected to the counter electrode terminal;

a base voltage source for supplying a base voltage to each of the working electrode voltage application section and the counter electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal during an assay.

25. The biosensor chip of claim 19, wherein

the reference terminal is connected to the counter electrode;

and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal;

a counter electrode voltage application section connected to the counter electrode terminal and the reference terminal and having an ammeter;

a base voltage source for supplying a base voltage to each of the counter electrode voltage application section and the working electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal during an assay.

26. The biosensor chip of claim 17, wherein the reference terminal includes:

a working electrode reference terminal connected to the working electrode; and

a counter electrode reference terminal connected to the counter electrode.

27. The biosensor chip of claim 26, wherein the measurement circuit includes:

a working electrode voltage application section connected to the working electrode terminal and the working electrode reference terminal;

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

a base voltage source for supplying a base voltage to each of the counter electrode voltage application section and the working electrode voltage application section; and

a signal processing circuit for processing at least one of a first current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal and a second current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal, during an assay.

28. The biosensor chip of claim 27, wherein the signal processing circuit processes both of the first current level signal and the second current level signal.

29. The biosensor chip of claim 17, wherein the substrate on which the biosensor is provided and the substrate on which the measurement circuit is provided are the same substrate.

30. The biosensor chip of claim 17, wherein:

the biosensor chip further includes a common substrate; and

the substrate on which the biosensor is provided and the substrate on which the measurement circuit is provided are mounted on the common substrate.

31. The biosensor chip of claim 17, wherein the substrate on which the biosensor is provided and the substrate on which the measurement circuit is provided are stacked on each other.

32. The biosensor chip of claim 17, wherein:

a plurality of the biosensors are provided on the same substrate, and at least two of the biosensors are connected to the same measurement circuit; and

a switch for turning ON/OFF a connection between each of the biosensors and the measurement circuit is further provided between the working electrode terminal of the biosensor and the measurement circuit, between the reference terminal of the biosensor and the measurement circuit, and between the counter electrode terminal of the biosensor and the measurement circuit.

33. The biosensor chip of claim 26, wherein a plurality of the biosensors are provided on the same substrate, and the sensor sections of two of the biosensors are provided adjacent to each other.

34. A biosensor device comprising:

a biosensor including;

a working electrode to be in contact with an assayed fluid during an assay;

a counter electrode to be in contact with the assayed fluid during an assay, the counter electrode opposing the working electrode with an interval therebetween for allowing a flow of the assayed fluid;

a sensor section for holding the assayed fluid;

a working electrode terminal connected to the working electrode;

a counter electrode terminal connected to the counter electrode; and

a reference terminal connected to one or both of the working electrode and the counter electrode, through which substantially no current flows during an assay, the biosensor being provided on a substrate; and

a measurement circuit connected to the biosensor and provided on a substrate,

wherein the biosensor device has a function of assaying a concentration of an assayed substance contained in the assayed fluid from one or both of a value of a current flowing through the working electrode terminal and a value of a current flowing through the counter electrode terminal during an assay.

35. The biosensor device of claim 34, wherein a biological substance or a microorganism that changes the assayed substance is immobilized on at least one of the working electrode and the counter electrode.

36. The biosensor device of claim 34, wherein the reference terminal is connected only to one of the working electrode and the counter electrode.

37. The biosensor device of claim 34, wherein:

the reference terminal includes;

a working electrode reference terminal connected to the working electrode; and

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

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal and the working electrode reference terminal;

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

a base voltage source for supplying a base voltage to each of the counter electrode voltage application section and the working electrode voltage application section; and

a signal processing circuit for processing at least one of a first current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal and a second current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal, during an assay.

38. The biosensor device of claim 34, wherein:

a voltage applied to the working electrode reference terminal is substantially equal to the base voltage supplied to the working electrode voltage application section during an assay; and

a voltage applied to the counter electrode reference terminal is substantially equal to the base voltage supplied to the counter electrode voltage application section during an assay.

39. The biosensor device of claim 34, further comprising a circuit connected to the measurement circuit for analyzing a signal output from the measurement circuit.

40. The biosensor device of claim 34, wherein:

the biosensor and the measurement circuit are provided on the same chip; and

the chip can be replaced with another.

41. The biosensor device of claim 37, wherein the measurement circuit further includes a current level signal generation section for receiving the first current level signal and the second current level signal to output, to the signal processing circuit, a third current level signal representing a level of a current flowing between the working electrode and the counter electrode.

42. The biosensor device of claim 36, wherein:

the reference terminal is connected to the working electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal and having an ammeter;

a working electrode potential reference circuit connected to the reference terminal;

a counter electrode voltage application section connected to the counter electrode terminal;

a base voltage source for supplying a base voltage to each of the working electrode potential reference circuit and the counter electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal during an assay.

43. The biosensor device of claim 42, wherein the working electrode potential reference circuit generates a signal so that a voltage applied to the reference terminal is substantially equal to the base voltage supplied to the working electrode potential reference circuit during an assay.

44. The biosensor device of claim 37, wherein:

the reference terminal is connected to the counter electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal;

a counter electrode voltage application section connected to the counter electrode terminal and having an ammeter;

a counter potential reference circuit connected to the reference terminal;

a base voltage source for supplying a base voltage to each of the counter electrode potential reference circuit and the working electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal during an assay.

45. The biosensor device of claim 44, wherein the counter electrode potential reference circuit generates a signal so that a voltage applied to the reference terminal is substantially equal to the base voltage supplied to the counter electrode potential reference circuit during an assay.

46. The biosensor device of claim 37, wherein:

the reference terminal is connected to the working electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal and the reference terminal and having an ammeter;

a counter electrode voltage application section connected to the counter electrode terminal;

a base voltage source for supplying a base voltage to each of the working electrode voltage application section and the counter electrode voltage application section; and

a signal processing circuit for processing a current level signal output from the working electrode voltage application section according to a level of a current flowing through the working electrode terminal during an assay.

47. The biosensor device of claim 37, wherein:

the reference terminal is connected to the counter electrode; and

the measurement circuit includes;

a working electrode voltage application section connected to the working electrode terminal;

a counter electrode voltage application section connected to the counter electrode terminal and the reference terminal and having an ammeter;

a base voltage source for supplying a base voltage to each of the counter electrode voltage application section and the working electrode voltage application section;

a signal processing circuit for processing a current level signal output from the counter electrode voltage application section according to a level of a current flowing through the counter electrode terminal during an assay.

48. The biosensor device of claim 34, wherein the device as a whole is disposable.