Electrochemical sensor

• US 20020029964A1
• Filed: 08/08/2001
• Published: 03/14/2002
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Matsumoto, Toru
• Granted Patent: US 6,773,563 B2
• Time in Patent Office: Days
• US Class Current: 204/403.1
• CPC Class Codes: C12Q 1/002 Electrode membranes

Abstract

An electrochemical sensor based on a three-electrode method containing a reference electrode, comprising: A working electrode 2, a counter electrode 3 and a reference electrode 4 formed on an insulating substrate 1; an examining electrode 8 provided to examine an electric potential of the reference electrode 4; a combining layer 20, an immobilized enzyme layer 21 and a diffusion-limiting layer 22 made of a fluororesin provided on voltmeter is provided on these electrodes, between the examining electrode 8 and the reference electrode 4 so that the electric potential of the reference electrode can be examined; to detect an abnormality in the reference electrode immediately after its occurrence, recover a high reliability of measured value by removing the abnormality quickly, make it possible to conduct a continuous measurement for a long time and furthermore try to reduce a running cost.

Claims

1. An electrochemical sensor having a working electrode, a counter electrode and a reference electrode, wherein a means for examining the reference electrode is provided for examining an electric potential of the reference electrode.

2. The electrochemical sensor as claimed in claim 1, wherein an immobilized enzyme layer is formed at least on the working electrode.

3. The electrochemical sensor as claimed in claim 2, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

4. The electrochemical sensor as claimed in claim 1, wherein a spare reference electrode is provided for use in place of the reference electrode when the means for examining the reference electrode detects an abnormal electric potential of the reference electrode.

5. The electrochemical sensor as claimed in claim 4, wherein an immobilized enzyme layer is formed at least on the working electrode.

6. The electrochemical sensor as claimed in claim 5, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

7. The electrochemical sensor as claimed in claim 4, wherein a means for switching the reference electrode is provided by which the spare reference electrode is used in place of the reference electrode when the abnormal electric potential is detected by the means for examining the reference electrode.

8. The electrochemical sensor as claimed in claim 7, wherein an immobilized enzyme layer is formed at least on the working electrode.

9. The electrochemical sensor as claimed in claim 8, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

10. The electrochemical sensor as claimed in claim 4, wherein a means for informing is provided to inform the time of replacing the reference electrode when the abnormal electric potential is detected by the means for examining the reference electrode.

11. The electrochemical sensor as claimed in claim 10, wherein an immobilized enzyme layer is formed at least on the working electrode.

12. The electrochemical sensor as claimed in claim 11, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

13. The electrochemical sensor as claimed in claim 10, wherein a means for switching the reference electrode is provided by which the spare reference electrode is used in place of the reference electrode when the abnormal electric potential is detected by the examining measures of the reference electrode.

14. The electrochemical sensor as claimed in claim 13, wherein an immobilized enzyme layer is formed at least on the working electrode.

15. The electrochemical sensor as claimed in claim 14, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

16. The electrochemical sensor as claimed in claim 1, wherein the means for examining the reference electrode comprises having an examining electrode as a standard to measure the electric potential of the reference electrode and a measuring apparatus by which a potential difference between the examining electrode and the reference electrode is measured.

17. The electrochemical sensor as claimed in claim 16, wherein an immobilized enzyme layer is formed at least on the working electrode.

18. The electrochemical sensor as claimed in claim 17, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

19. The electrochemical sensor as claimed in claim 16, wherein a spare reference electrode is provided for use in place of the reference electrode when the means for examining the reference electrode detects an abnormal electric potential of the reference electrode.

20. The electrochemical sensor as claimed in claim 19, wherein an immobilized enzyme layer is formed at least on the working electrode.

21. The electrochemical sensor as claimed in claim 20, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

22. The electrochemical sensor as claimed in claim 19, wherein a means for switching the reference electrode is provided by which the spare reference electrode is used in place of the reference electrode when the abnormal electric potential is detected by the means for examining the reference electrode.

23. The electrochemical sensor as claimed in claim 22, wherein an immobilized enzyme layer is formed at least on the working electrode.

24. The electrochemical sensor as claimed in claim 23, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

25. The electrochemical sensor as claimed in claim 19, wherein a means for informing is provided to inform the time of replacing the reference electrode when the abnormal electric potential is detected by the means for examining the reference electrode.

26. The electrochemical sensor as claimed in claim 25, wherein an immobilized enzyme layer is formed at least on the working electrode.

27. The electrochemical sensor as claimed in claim 26, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

28. The electrochemical sensor as claimed in claim 25, wherein a means for switching the reference electrode is provided by which the spare reference electrode is used in place of the reference electrode when the abnormal electric potential is detected by the means for examining the reference electrode.

29. The electrochemical sensor as claimed in claim 28, wherein an immobilized enzyme layer is formed at least on the working electrode.

30. The electrochemical sensor as claimed in claim 29, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

31. An electrochemical sensor having a working electrode, a counter electrode and a reference electrode, wherein a spare electrode is provided for use in palace of the reference electrode when a use of the reference electrode is stopped.

32. The electrochemical sensor as claimed in claim 31, wherein an immobilized enzyme layer is formed at least on the working electrode.

33. The electrochemical sensor as claimed in claim 32, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.

34. The electrochemical sensor as claimed in claim 31, wherein a means for switching the reference electrode is provided by which the spare reference electrode is used in place of the reference electrode when the use of the reference electrode is stopped.

35. The electrochemical sensor as claimed in claim 34, wherein an immobilized enzyme layer is formed at least on the working electrode.

36. The electrochemical sensor as claimed in claim 35, wherein a diffusion-limiting layer containing fluoroalcohol ester of polycarboxylic acid, which is formed so as to cover at least the working electrode and the reference electrode, is provided on the immobilized enzyme layer.