Enzymatic electrochemical biosensor

• US 20070080073A1
• Filed: 10/22/2004
• Published: 04/12/2007
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Blaschke, Christina, Wu, Huang-Ping, Beer, Greg
• Granted Patent: US 8,007,656 B2
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

An electrochemical sensor strip has a base and a first electrode and a second electrode on the base. An oxidoreductase enzyme and a mediator are on the first electrode, and a soluble redox species is on the second electrode. The soluble redox species may be an organotransition metal complex, a transition metal coordination complex, an electroactive organic molecule, or mixtures thereof.

Claims

1. An electrochemical sensor strip, comprising:

a base;

a first electrode on the base;

a first reagent layer on the first electrode, the first reagent layer comprising an electroactive organic molecule and an oxidoreductase capable of facilitating a redox reaction of a substrate;

a second electrode on the base; and

a second reagent layer on the second electrode, the second reagent layer comprising a first soluble redox species selected from the group consisting of an organotransition metal complex, a transition metal coordination complex and mixtures thereof, the first soluble redox species being capable of undergoing a redox reaction opposite that of the substrate.

2. The electrochemical sensor strip of claim 1, wherein the composition of the first reagent layer is different from the composition of the second reagent layer.

6. The electrochemical sensor strip of claim 2, wherein the second reagent layer further comprises a second redox species, the second redox species being a species of a redox pair comprising the first soluble redox species and the second redox species, and wherein the molar ratio of the first soluble redox species to the second redox species is greater than 1.2:

1.

7. The electrochemical sensor strip of claim 6, wherein the molar ratio of the first soluble redox species to the second redox species is greater than 2:

1.

13. The electrochemical sensor strip of claim 1, wherein the first soluble redox species comprises ferrocyanide or ferricyanide.

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

15. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule is selected from the group consisting of 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, 3-phenylimino-3H-phenoxazines, and mixtures thereof.

16. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule comprises a 3 -phenylimino-3 H-phenothiazine.

17. The electrochemical sensor strip of claim 1, wherein the electroactive organic molecule comprises a 3-phenylimino-3H-phenoxazine.

22. The electrochemical sensor strip of claim 1, further comprising a lid.

26. The electrochemical sensor strip of claim 1, further comprising a third electrode on the base and a third reagent layer on the third electrode, the third reagent layer comprising a third soluble redox species.

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30. An electrochemical sensor strip, comprising:

a base;

a first electrode on the base;

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

a second electrode on the base; and

a second reagent layer on the second electrode, the second reagent layer comprising a first soluble redox species selected from the group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof, the first soluble redox species being a reducible species.

31. The electrochemical sensor strip of claim 30, wherein the composition of the first reagent layer is different from the composition of the second reagent layer.

33. The electrochemical sensor strip of claim 30, wherein the electroactive organic molecule is selected from the group consisting of 3-phenylimino-3H-phenothiazines, 3-phenylimino-3 H-phenoxazines, and mixtures thereof.

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37. A method of making an electrochemical sensor strip, the method comprising the acts of:

depositing a first electrode on a base;

depositing a second electrode on the base;

applying a first reagent layer on the first electrode, the first reagent layer comprising an electroactive organic molecule and an oxidoreductase capable of facilitating a redox reaction of a substrate; and

applying a second reagent layer on the second electrode, the second reagent layer comprising a first soluble redox species selected from the group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof, the first soluble redox species being capable of undergoing a redox reaction opposite that of the substrate.

38. The method of claim 37, wherein the oxidoreductase comprises an enzyme selected from the group consisting of an oxidase and a dehydrogenase, and wherein the soluble redox species is a reducible species.

45. The method of claim 37, further comprising mating a lid to the base such that the lid is over the first and second electrodes and the first and second reagent layers.

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61. A method of quantifying an analyte in a sample, the method comprising the acts of:

contacting the sample with an electrochemical sensor strip, the electrochemical sensor strip comprising a first electrode and a first reagent layer on the first electrode, the first reagent layer comprising an electroactive organic molecule and an oxidoreductase capable of facilitating a redox reaction of a substrate, the electrochemical sensor strip further comprising a second electrode and a second reagent layer on the second electrode, the second reagent layer comprising a soluble redox species selected from the group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof, the soluble redox species being capable of undergoing a redox reaction opposite that of the substrate;

applying an electrical potential between the first and second electrodes;

measuring a current passing through the first and second electrodes and the sample; and

correlating the current to a concentration of the analyte.

65. The method of claim 61, wherein the oxidoreductase comprises an enzyme selected from the group consisting of an oxidase and a dehydrogenase, the soluble redox species being a reducible species.

68. The method of claim 61, wherein the analyte comprises glucose, and the oxidoreductase comprises glucose oxidase or glucose dehydrogenase.

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