Electrochemical sensor strip

• US 9,803,228 B2
• Filed: 09/01/2015
• Issued: 10/31/2017
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Inventors: Wu, Huan-Ping, Beer, Greg P., Blaschke, Christina
• Primary Examiner(s): Hendricks, Keith
• Assistant Examiner(s): CARLSON, KOURTNEY SALZMAN
• Application Number:
  US14/842,286
• Publication Number:
  US 20150368688A1
• Time in Patent Office: 791 Days
• Field of Search: 20440301-40315, 204412, 205775, 2057775, 205792, 205789
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

A method of making an electrochemical sensor strip that includes: depositing a first electrode on a base; depositing a second electrode on the base; applying a first layer onto the first electrode; and applying a second layer onto the second electrode. The first layer includes an oxidoreductase and a mediator. The second layer includes a soluble redox species.

Claims

1. An electrochemical sensor strip for analyzing an analyte in a test sample, the electrochemical sensor strip comprising:

a base;

a first electrode attached to the base;

a first reagent layer disposed on the first electrode, the first reagent layer including an electroactive organic molecule and an oxidoreductase, the oxidoreductase being configured to facilitate a redox reaction of the analyte;

a second electrode attached to the base; and

a second reagent layer disposed on the second electrode, the second reagent layer consisting essentially of a redox pair with first and second soluble redox species configured to undergo redox reactions, wherein the redox pair is selected from a group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof.

2. The electrochemical sensor strip of claim 1, wherein a molar ratio of the first soluble redox species to the second soluble redox species is greater than approximately 1.2:

1 prior to use of the sensor strip to analyze the analyte.

3. The electrochemical sensor strip of claim 1, wherein the first soluble redox species comprises at least one of ruthenium(II) hexaamine or ruthenium(III) hexaamine.

4. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule includes coenzyme pyrroloquinoline quinone (PQQ), substituted benzoquinones, substituted naphthoquinones, N-oxides, nitroso compounds, hydroxylamines, oxines, flavins, phenazines, phenothiazines, indophenols, indamines, phenazinium salts, phenoxazinium salts, 3-phenylimino-3H-phenothiazines, or 3-phenylimino-3H-phenoxazines, or any mixture thereof.

5. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule includes at least one a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine.

6. The electrochemical sensor strip of claim 1, wherein the first soluble redox species is configured to undergo a first redox reaction, and the second soluble redox species is configured to undergo a second redox reaction opposite to that of the first soluble redox species.

7. The electrochemical sensor strip of claim 1, further comprising:

a third electrode attached to the base; and

a third reagent layer disposed on the third electrode, the third reagent layer including a third soluble redox species.

8. The electrochemical sensor strip of claim 7, wherein the third soluble redox species is substantially identical to the first soluble redox species.

9. The electrochemical sensor strip of claim 1, wherein the second soluble redox species is present in an amount less than about 1 part per thousand.

10. The electrochemical sensor strip of claim 1, wherein the first soluble redox species has a standard reduction potential of at least about +0.24 volts.

11. The electrochemical sensor strip of claim 1, wherein the first soluble redox species has a standard reduction potential of at least about +0.35 volts.

12. The electrochemical sensor strip of claim 1, further comprising a lid mated to the base such that the lid is positioned over the first and second electrodes and the first and second reagent layers.

13. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule and the oxidoreductase are substantially present only in the first reagent layer, and the first soluble redox species is substantially present only in the second reagent layer.

14. The electrochemical sensor strip of claim 1, wherein the first and second soluble redox species are substantially present only in the second reagent layer.

15. An electrochemical sensor strip for analyzing an analyte in a test sample, the electrochemical sensor strip comprising:

a base;

a first electrode attached to the base;

a first reagent layer disposed on the first electrode, the first reagent layer including an electroactive organic molecule and an enzyme, the enzyme being selected from a group consisting of glucose oxidase, glucose dehydrogenase, and mixtures thereof;

a second electrode attached to the base; and

a second reagent layer disposed on the second electrode, the second reagent layer consisting essentially of a redox pair with first and second soluble redox species configured to undergo redox reactions, wherein the redox pair is selected from a group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof.

16. The electrochemical sensor strip of claim 15, wherein a molar ratio of the first soluble redox species to the second soluble redox species is greater than approximately 1.2:

1 prior to use of the sensor strip to analyze the analyte.

17. The electrochemical sensor strip of claim 15, wherein the first soluble redox species includes at least one of ruthenium(II) hexaamine or ruthenium(III) hexaamine.

18. The electrochemical sensor strip of claim 15, wherein the electroactive organic molecule includes coenzyme pyrroloquinoline quinone (PQQ), substituted benzoquinones, substituted naphthoquinones, N-oxides, nitroso compounds, hydroxylamines, oxines, flavins, phenazines, phenothiazines, indophenols, indamines, phenazinium salts, phenoxazinium salts, 3-phenylimino-3H-phenothiazines, or 3-phenylimino-3H-phenoxazines, or any mixture thereof.

19. The electrochemical sensor strip of claim 15, wherein the electroactive organic molecule includes at least one of a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine.

20. The electrochemical sensor strip of claim 15, wherein the electroactive organic molecule and the enzyme are substantially present only in the first reagent layer, and the first soluble redox species is substantially present only in the second reagent layer.

21. The electrochemical sensor strip of claim 15, further comprising:

a third electrode attached to the base; and

a third reagent layer disposed on the third electrode, the third reagent layer including a third soluble redox species.

22. The electrochemical sensor strip of claim 21, wherein the third soluble redox species is substantially identical to the first soluble redox species.

23. The electrochemical sensor strip of claim 15, wherein the second soluble redox species is present in an amount less than about 1 part per thousand.

24. The electrochemical sensor strip of claim 15, wherein the first soluble redox species has a standard reduction potential of at least about +0.24 volts.

25. The electrochemical sensor strip of claim 15, wherein the first soluble redox species has a standard reduction potential of at least about +0.35 volts.

26. The electrochemical sensor strip of claim 15, further comprising a lid mated to the base such that the lid is positioned over the first and second electrodes and the first and second reagent layers.

27. The electrochemical sensor strip of claim 15, wherein the first soluble redox species is configured to undergo a first redox reaction, and the second soluble redox species is configured to undergo a second redox reaction opposite to that of the first soluble redox species.

28. The electrochemical sensor strip of claim 15, wherein the first and second soluble redox species are substantially present only in the second reagent layer.