ELECTRODE PRECONDITIONING

• US 20100140108A1
• Filed: 06/28/2006
• Published: 06/10/2010
• Est. Priority Date: 06/29/2005
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Hyland, Mark, Newman, Christopher Paul, Roblin, Patricia Mary Elizabeth
• Granted Patent: US 8,518,236 B2
• Time in Patent Office: Days
• US Class Current: 205/775
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements

Abstract

A method for improving the precision of electrochemical measurements made using an electrochemical cell is provided. The method comprises preconditioning a working electrode of the cell by (i) baking the working electrode; and/or (ii) incubating the working electrode; and/or (iii) applying a preconditioning potential across the cell; and/or (iv) treating the working electrode with a UV laser.

Claims

1. A method of preparing an electrochemical device, said method comprising:

(a) providing an electrochemical cell having a working electrode and a pseudo reference electrode;

(b) preconditioning the working electrode by (i) baking the working electrode; and

/or (ii) incubating the working electrode; and

/or (iii) applying a preconditioning potential across the cell; and

/or (iv) treating the working electrode with a UV laser; and

(c) providing an electroactive reagent to the electrochemical cell and optionally drying the reagent

2. A method according to claim 1, which further comprises

(d) supplying a sample to the device, the sample being in contact with the working electrode and with the electroactive reagent;

and

(e) applying a measuring potential across the cell and measuring the resulting electrochemical response.

3. A method according to claim 1 or 2, wherein the electroactive reagent comprises an electrochemical mediator.

4. A method according to claim 3, wherein the mediator is a ruthenium complex or a ferricyanide or ferrocyanide salt.

5. A method according to any one of the preceding claims, wherein the electroactive reagent is substantially free of metals capable of adsorbing to the working electrode.

6. A method according to any one of the preceding claims, wherein the electroactive reagent does not contain cobalt.

7. A method according to any one of the preceding claims, wherein the preconditioning potential is applied in the presence of an aqueous buffer which contacts the working and pseudo reference electrodes.

8. A method according to any one of the preceding claims, wherein the preconditioning potential is applied by carrying out a scan of the potential between −

0.1V and +1.8V.

9. A method according to any one of claims 1 to 7, wherein the preconditioning potential is applied by stepping the potential to a value of between −

0.1V and +1.8V.

10. A method according to any one of claims 2 to 9, wherein the preconditioning potential is applied after supplying the sample to the device in step (d).

11. A method according to any one of the preceding claims, wherein baking is carried out at a temperature of up to 150°

C. for a period of up to 48 hours.

12. A method according to any one of the preceding claims, wherein baking is carried out at about 130°

C. for about 30 minutes, or at about 100°

C. for about 2 hours.

13. A method according to any one of the preceding claims, wherein incubation is carried out at a temperature of from −

20°

C. to 30°

C. for up to 30 days.

14. A method according to any one of the preceding claims, wherein the working electrode has at least one dimension of less than 50 μ

m.

15. A method according to any one of the preceding claims, wherein the electrochemical cell is in the form of a receptacle, the working electrode is in a wall of the receptacle and the method comprises inserting the electroactive reagent into the receptacle.

16. A method according to any one of the preceding claims, wherein the device comprises a strip having at least one receptacle or partial receptacle formed therein, the receptacle or partial receptacle having a first open part in a first surface of the strip to enable a sample to enter the receptacle or partial receptacle,

wherein the working electrode of the electrochemical cell is in a wall or walls of the receptacle or partial receptacle,

wherein the pseudo reference electrode of the electrochemical cell comprises a pseudo reference electrode layer formed on at least a part of the first surface of the strip, and

wherein the method comprises inserting the electroactive reagent into the receptacle.

17. An electrochemical device which is obtained or obtainable by the method of any one of the preceding claims.

18. A device according to claim 17 comprising

an electrochemical cell having a working electrode and a pseudo reference electrode;

an electroactive reagent comprising an electrochemical mediator;

a potentiostat for applying a potential between the working and pseudo reference electrodes;

a controller for controlling the potentiostat; and

means for measuring the electrochemical response of the cell;

wherein the working electrode is a preconditioned electrode obtained by subjecting the working electrode to (i) baking; and

/or (ii) incubating; and

/or (iii) a preconditioning potential; and

/or (iv) treatment with a UV laser.

21. An electrochemical sensing method comprising providing a sample to an electrochemical device according to any one of claims 17 to 20, applying a potential across the electrochemical cell and measuring the resulting electrochemical response.

19. A device comprising

an electrochemical cell having a working electrode and a pseudo reference electrode;

an electroactive reagent comprising an electrochemical mediator;

a potentiostat for applying a potential between the working and pseudo reference electrodes;

a controller for controlling the potentiostat so that firstly a preconditioning potential is applied and subsequently a measuring potential is applied; and

means for measuring the electrochemical response of the cell.

20. A device according to claim 19, wherein the working electrode is a preconditioned electrode obtained by subjecting the electrode to (i) baking;

and/or (ii) incubating; and

/or (iii) a preconditioning potential and/or (iv) treatment with a UV laser.

22. A method of improving the precision of electrochemical measurements made using an electrochemical cell, said method comprising preconditioning a working electrode of the cell by (i) baking the working electrode;

and/or (ii) incubating the working electrode; and

/or (iii) applying a preconditioning potential across the cell; and

/or (iv) treating the working electrode with a UV laser.