Electrodes, methods, apparatuses comprising micro-electrode arrays

• US 20030155237A1
• Filed: 10/04/2002
• Published: 08/21/2003
• Est. Priority Date: 11/16/2001
• Status: Active Grant

• Current Assignee: Christopher D. Wilsey, Nigel A. Surridge
• Original Assignee: Corange International Limited (Roche Holding AG)
• Inventors: Wilsey, Christopher D., Surridge, Nigel A.
• Granted Patent: US 7,276,146 B2
• Time in Patent Office: Days
• US Class Current: 204/403.14
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875

Abstract

Described are micro-arrays of electrodes disposed proximal to a flexible substrate, electronic components and sensors comprising such arrays, and methods of use for such arrays.

Claims

1. An electrochemical sensor for detection of an analyte in a test sample, said sensor comprising:

a substrate having a working electrode and a counter electrode formed thereon;

a chemical coating deposited into a chamber formed on the substrate over the working and counter electrodes;

said chemical coating comprising an enzyme and a mediator in a matrix, wherein said sensor provides an accurate reading of the amount of analyte in the test sample within 10 seconds or less after deposition of the test sample to the chamber.

2. The sensor of claim 1 wherein the working electrode and the counter electrode are separated by a gap of less than about 300 μ

m.

3. The sensor of claim 2 wherein the working electrode and the counter electrode are separated by a gap of less than about 150 μ

m.

4. The sensor of claim 3 wherein the working electrode and the counter electrode are separated by a gap of less than about 50 μ

m.

5. The sensor of claim 1 wherein the chamber has a sample volume of less than about 1.45 μ

l.

6. The sensor of claim 1 wherein the chamber has a sample volume of between about 0.1 and about 0.4 μ

l.

7. The sensor of claim 1 wherein the chemical coating comprises glucose-dye-oxidoreductase, glucose oxidase, glucose dehydrogenase, diaphorase, and optionally a cofactor.

8. The sensor of claim 7 wherein the chemical coating comprises glucose-dye-oxidoreductase.

9. The sensor of claim 1 wherein the mediator is selected from the group consisting of:

osmium (III)-bipyridyl-2-imidazolyl-chloride, Meldola blue, Ru(NH₃)₅pyz]₂(SO₄)₃, a ferricyanide salt, a nitrosoanaline derivative, and mixtures thereof.

10. The sensor of claim 9 wherein the mediator is a ferricyanide salt or a nitrosoanaline derivative.

11. The sensor of claim 1 wherein the sensor provides an accurate reading of the analyte after a delay period of between about 2 seconds and about 6 seconds.

12. The sensor of claim 1 providing an accurate reading of the analyte amount in the test sample within 5 seconds or less after depositing the test sample into the chamber.

13. The sensor of claim 12 wherein the sensor provides an accurate reading of the analyte after a delay period of between about 2 seconds and less than about 5 seconds.

14. The sensor of claim 12 providing an accurate reading of the analyte amount in the test sample within 3 seconds or less after depositing the test sample into the chamber.

15. The sensor of claim 14 wherein the sensor provides an accurate reading of the analyte after a delay period of between about 2 seconds and less than about 3 seconds.

16. The sensor of claim 1 wherein the working electrode has a width of between about 15 μ

m and about 500 μ

m.

17. The sensor of claim 1 wherein the analyte is selected from the group consisting of glucose, cholesterol, HDL cholesterol, triglycerides, lactate, lactate dehydrogenase, pyruvate, alcohol, uric acid, and 3-hydroxybutyric acid.

18. The sensor of claim 17 wherein the analyte is glucose.

19. The sensor of claim 1 wherein the test sample comprises blood.

20. The sensor of claim 1 wherein the substrate is flexible.

21. The sensor of claim 1 wherein the substrate is rigid.

22. A method of evaluating the concentration of an analyte in a test sample, said method comprising supplying the test sample to the chamber of the sensor of claim 1.

23. A method of evaluating the concentration of an analyte in a test sample, said method comprising:

supplying a test sample containing the analyte to a chamber on a sensor, said sensor comprising a working electrode, a counter electrode, and a chemical coating deposited therein, said chemical coating including an enzyme and a mediator;

applying a voltage potential across the working electrode and the counter electrode,

measuring a stable current generated at the working electrode within 10 seconds or less after said depositing.

24. The method of claim 23 wherein said supplying comprises supplying between about 0.300 and about 1.5 μ

m of the test sample.