Method of making an electrochemical sensor strip

• US 10,457,971 B2
• Filed: 09/27/2017
• Issued: 10/29/2019
• 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): Noguerola, Alexander S
• Application Number:
  US15/717,160
• Publication Number:
  US 20180016615A1
• Time in Patent Office: 762 Days
• 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. A method of making an electrochemical sensor strip, the method comprising:

depositing a first electrode on a base;

depositing a second electrode on the base;

applying a first reagent layer onto the first electrode, the first reagent layer comprising an electroactive organic molecule and an oxidoreductase configured to facilitate a redox reaction of an analyte; and

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

2. The method of claim 1, wherein the first soluble redox species comprises at least one of ruthenium(II) hexaamine or ruthenium(III) hexaamine.

3. The method of claim 1, wherein the electroactive organic molecule includes coenzyme pyrroloquinoline quinone, 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.

4. The method of claim 1, wherein the electroactive organic molecule includes at least one of a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine.

5. The method of claim 1, wherein the analyte comprises glucose.

6. The method of claim 5, wherein the oxidoreductase comprises glucose oxidase, glucose dehydrogenase, or a combination thereof.

7. The method of claim 1, further comprising covering a portion of the base with a dielectric layer such that the first and second reagent layers are exposed.

8. The method of claim 1, 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.

9. The method of claim 1, wherein the depositing of the second electrode comprises depositing a pattern of a non-ionizing conductive material.

10. The method of claim 1, further comprising:

depositing a third electrode on the base; and

applying a third reagent layer onto the third electrode, the third reagent layer comprising a third soluble redox species.

11. The method of claim 10, wherein the third soluble redox species is substantially identical to the first soluble redox species of the second reagent layer.

12. The method of claim 10, wherein the composition of the third reagent layer is substantially identical to the composition of the second reagent layer.

13. The method of claim 1, wherein the first soluble redox species has a standard reduction potential of at least about +0.24 volts.

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

forming a first connecting conductor on a base, the first connecting conductor extending to a proximal edge of the base, and the base being formed of an insulating material;

forming a second connecting conductor on the base, the second connecting conductor extending to the proximal edge of the base;

forming a first main conductor on the base contiguous to a distal end of the first connecting conductor;

forming a second main conductor on the base contiguous to a distal end of the second connecting conductor;

applying a first reagent layer onto the first main conductor, the first reagent layer comprising an electroactive organic molecule and an oxidoreductase configured to facilitate a redox reaction of an analyte; and

applying a second reagent layer onto the second main conductor, the second reagent layer consisting essentially of a redox pair comprising a first soluble redox species and a second soluble redox species, the redox pair being selected from a group consisting of an organotransition metal complex, a transition metal coordination complex, and mixtures thereof.

15. The method of claim 14, wherein the first connecting conductor and the first main conductor are formed of a first continuous strip of metal foil, and the second connecting conductor and the second main conductor are formed of a second continuous strip of metal foil.

16. The method of claim 15, further comprising:

forming a first surface conductor on the first main conductor and below the first reagent layer; and

forming a second surface conductor on the second main conductor and below the second reagent layer.

17. The method of claim 16, wherein the first surface conductor and the second surface conductor are formed of conductive carbon.

18. The method of claim 14, further comprising:

forming a third connecting conductor on the base, the third connecting conductor extending to the proximal edge of the base;

forming a third main conductor on the base contiguous to a distal end of the third connecting conductor; and

applying a third reagent layer onto the third main conductor, the third reagent layer comprising a third soluble redox species.

19. The method of claim 18, further comprising forming a surface conductor on the third main conductor and below the third reagent layer.

20. The method of claim 19, wherein the third connecting conductor and the third main conductor are formed of a continuous strip of metal foil, and the surface conductor is formed of conductive carbon.