Micro-band electrode

• US 20050178674A1
• Filed: 12/23/2002
• Published: 08/18/2005
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Wallace-Davies, Emma Naomi Kathlene, Lorimer, Kevin, Astier, Yann, Butler, Ronald Neil, Hyland, Mark
• Granted Patent: US 7,972,487 B2
• 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
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

The invention concerns an electrochemical cell which, either alone or together which a substrate onto which it is placed, is in the form of a receptacle. The electrochemical cell contains a working electrode and a counter electrode, the working electrode being in a wall of the receptacle. At least one of the electrodes has at least one dimension of less than 50 μm. The electrochemical cell is principally intended for use as a micro-electrode suitable for screening water, blood, urine or other biological or non-biological fluids.

Claims

1. An electrochemical cell which, either alone or in combination with a substrate onto which it is placed, is in the form of a receptacle, said cell comprising a counter electrode and a working electrode, wherein at least one electrode has at least one dimension of less than 50 μ

m, the working electrode being in a wall of the receptacle.

2. An electrochemical cell according to claim 1 which is in the form of a receptacle.

3. An electrochemical cell according to claim 1, wherein the working electrode is in the form of a continuous band.

4. An electrochemical cell according to claim 1, which further comprises a reference electrode.

5. An electrochemical cell according to claim 1, wherein the ratio of the surface area of the counter electrode to the surface area of the working electrode is at least 25:

1.

6. An electrochemical cell according to claim 1, wherein the working electrode has at least one dimension in the range of 0.1 to 20 μ

m.

7. An electrochemical cell according to claim 1, wherein the receptacle has a width of from 0.1 to 5 mm.

8. An electrochemical cell according to claim 1, wherein the minimum distance between the counter electrode and the working electrode is from 10 to 1000 μ

m.

9. An electrochemical cell according to claim 1, wherein a base and/or a wall or walls of the receptacle contain one or more air-outlet channels.

10. An electrochemical cell according to claim 1, wherein the receptacle contains an electro-active substance.

11. An electrochemical cell according to claim 10, wherein the electro-active substance has been dried.

12. An electrochemical cell according to claim 10, wherein the electro-active substance comprises an enzyme.

13. An electrochemical cell according to claim 10, wherein the base of the receptacle comprises an electro-active substance.

14. An electrochemical cell according to claim 10, wherein the base of the receptacle comprises a membrane, said membrane comprising an electro-active substance.

15. An electrochemical cell according to claim 1, wherein the open end of the receptacle is at least partly covered by a permeable membrane.

16. An electrochemical cell according to claim 15 wherein the permeable membrane comprises an electro-active substance.

17. An electrochemical cell according to claim 1, wherein the receptacle comprises one or more capiliary flow channels through which a sample may enter.

18. An electrochemical cell according to claim 1, wherein the counter electrode forms at least a part of a base of the receptacle.

19. An electrochemical cell according to claim 17, wherein the receptacle is covered by a layer containing the counter electrode.

20. An electrochemical cell according to claim 1, wherein the counter electrode is in a wall or walls of the receptacle.

21. An electrochemical cell according to claim 1 which is suitable for screening liquid samples.

22. A multi-analyte device comprising a plurality of electrochemical cells according to claim 1.

23. A process for producing an electrochemical cell according to claim 1, which process comprises the steps of:

(a) forming a first part comprising an insulating material which is optionally coated with a counter electrode layer;

(b) forming a second part comprising a laminate of a working electrode layer between two layers of an insulating material;

(c) creating a hole in the second part; and

(d) bonding said first part to said second part to form a receptacle.

24. A process according to claim 23 wherein the second part comprises a laminate of a counter electrode layer between two layers of insulating material.

25. A process according to claim 23 wherein the first part comprises an electro-active substance.

26. A process according to claim 23 which further comprises placing an electro-active substance into the receptacle and optionally drying the electro-active substance.

27. A process according to claim 23, which further comprises placing a membrane over at least a part of the open end of the receptacle.

28. A process according to claim 23, wherein step (c) comprises forming two or more holes in said second part, in order to form a multi-analyte device.

29. A process for producing an electrochemical cell according to claim 1, which comprises the steps of:

(a) forming a second part comprising a laminate of a working electrode layer between two layers of an insulating material;

(b) creating a hole in the second part; and

optionally

(c) bonding to said second part a layer which is coated with a counter electrode material.

30. A process according to claim 29, wherein the second part comprises a laminate of a counter electrode layer between two layers of insulating material.

31. A process according to claim 23 which comprises the steps of:

(a) forming a first part comprising an insulating material;

(b) forming a second part comprising a laminate of a working electrode layer between two layers of an insulating material;

(c) creating, in the second part, a hole and a capiliary channel to allow a sample to enter said hole;

(d) bonding said first part to said second part to form a receptacle;

(e) placing an electro-active substance into the receptacle and optionally drying the electro-active substance; and

(f) bonding to the open end of said receptacle a layer which is optionally coated with a counter electrode material.

32. A process according to claim 31, wherein step (c) comprises forming, in said second part, two or more holes and two or more capiliary channels to allow a sample to enter said two or more holes, and wherein step (e) comprises inserting an electro-active substance, which may be identical or different, into one or more of the receptacles formed in step (d), in order to form a multi-analyte device.

33. A modification of the process of claim 31 which comprises the steps (a), (b), (c), (d) and (f) as defined in claim 31 and in which the first part comprises an electro-active substance.

34. A process according to claim 23, wherein one or more of the electrodes is formed by screen or inkjet printing onto a substrate.

36. A multi-analyte device comprising a plurality of electrochemical cells as defined in claim 10.

37. A multi-analyte device comprising a plurality of electrochemical cells as defined in claim 15.

35. A method of electrochemically testing one or more compounds of a sample, the method comprising the steps of:

(a) providing an electrochemical cell which, either alone or in combination with a substrate onto which it is placed, is in the form of a receptacle, said cell comprising a counter electrode and a working electrode at least one of which has at least one dimension of less than 50 μ

m wherein the working electrode being in a wall of the receptacle

(b) inserting the sample into the electrochemical cell;

(c) applying a voltage or a current between the working and counter electrodes; and

(d) measuring the resulting current, voltage or charge across the working and counter electrodes.