Heated electrochemical cell

• US 20030080001A1
• Filed: 09/16/2002
• Published: 05/01/2003
• Est. Priority Date: 03/12/1998
• Status: Abandoned Application

• Current Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Hodges, Alastair, Beck, Thomas W.
• Application Number:
  US10/246,370
• Publication Number:
  US 20030080001A1
• Time in Patent Office: Days
• US Class Current: 205/775
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

The invention provides a method for determining the concentration of an analyte in a sample comprising the steps of heating the sample and measuring the concentration of the analyte or the concentration of a species representative thereof in the sample at a predetermined point on a reaction profile by means that are substantially independent of temperature. Also provided is an electrochemical cell comprising a spacer pierced by an aperture which defines a cell wall, a first metal electrode on one side of the spacer extending over one side of the aperture, a second metal electrode on the other side of the spacer extending over the side of the aperture opposite the first electrode, means for admitting a sample to the cell volume defined between the electrodes and the cell wall, and means for heating a sample contained within the cell.

Claims

1. A method for determining a concentration of an analyte in a sample comprising the steps of:

heating the sample in a disposable test cell; and

measuring the concentration of the analyte or a concentration of a species representative of the analyte in the sample at a predetermined point on a reaction profile by means that are substantially independent of the temperature of the sample in the test cell.

2. The method according to claim 1 wherein the predetermined point on the reaction profile is a steady state.

3. The method according to claim 1 wherein the species representative of the concentration of the analyte is a mediator.

4. The method according to claim 3 wherein the mediator is an enzyme mediator.

5. The method according to claim 1 wherein the sample is heated by an exothermic reaction produced upon contact of said sample with at least one suitable reagent.

6. The method according to claim 5 wherein the at least one suitable reagent is a salt which liberates heat on dissolution.

7. The method according to claim 6 wherein the salts are selected from the group consisting of aluminium chloride, lithium halides, lithium sulfate, magnesium halides, and magnesium sulfate.

8. The method according to claim 5 wherein the at least one suitable reagent is a two component system which liberates heat upon mixing.

9. The method according to claim 8 wherein each of the two components are placed in separate locations in a sensor during fabrication.

10. The method according to claim 9 wherein said two components are placed as coatings upon opposite internal cell walls of a sensor.

11. The method according to claim 1 wherein the sample is heated electrically.

12. The method according to claim 11 wherein said sample is heated by means of a current applied to resistive elements associated with said measuring means.

13. The method according to claim 1 wherein the concentration of the analyte is measured by an electrochemical measurement.

14. The method according to claim 13 wherein the sample is heated prior to and/or during conduct of the electrochemical measurement.

15. The method according to claim 1 wherein the sample temperature is raised by from 5 to 15°

C.

16. The method according to claim 1 wherein the sample temperature is raised within a period of 2-10 seconds.

17. The method according to claim 1 wherein a peak temperature is reached with 2-5 seconds.

18. The method according to claim 1 wherein the analyte is glucose.

19. The method according to claim 1 wherein the sample is blood.

20. The method according to claim 19 wherein the blood sample is combined with an enzyme.

21. The method according to claim 20 wherein the enzyme is glucose dehydrogenase (GDH) which oxidises glucose and is converted to reduced GDH.

22. The method according to claim 21 wherein an oxidising mediator is present.

23. The method according to claim 22 wherein said oxidising mediator is ferricyanide.

24. The method according to claim 23 wherein said ferricyanide reacts with said produced GDH to produce ferrocyanide.

25. The method according to claim 24 wherein the ferrocyanide produced is sensed to produce a signal representative of the glucose concentration of the sample.

26. The method according to claim 25 wherein the sensing is by electrochemical means.

27. The method according to claim 25 wherein the sensing is by a spectroscopic means.