Microelectrode biosensor and method therefor

• US 6,740,214 B1
• Filed: 03/12/2001
• Issued: 05/25/2004
• Est. Priority Date: 05/08/1998
• Status: Expired due to Fees

• Current Assignee: Isis Innovation Limited
• Original Assignee: Isis Innovation Limited
• Inventors: Nakagawa, Yasue, Leigh, Peter Alexander, Hill, Hugh Allen Oliver, Dobson, Peter James
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US09/674,991
• Time in Patent Office: 1,170 Days
• Field of Search: 204/403.01, 204/403.04, 204/403.05, 204/403.07, 204/403.09, 204/403.1, 204/403.13, 204/403.14, 204/403.08, 427/2.13
• US Class Current: 204/403.1
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies

Abstract

There is disclosed a biosensor comprising a conducting surface, a layer of dielectric material overlying the conducting surface, a plurality of micro electrodes constituted by a plurality of pores extending through the thickness of said dielectric layer, a biopolymer positioned on the conducting surface in said pores, and a counter electrode arranged such that electrical connection can be made between it and at least part of said conducting surface by a fluid to be assessed. Such a device can be made using a method comprising the steps of providing a conducting surface;

providing a layer of dielectric material adjacent to said conducting surface, said dielectric material comprising a plurality of pores extending through the thickness of the dielectric layer;

providing a biopolymer on the conducting surface in said pores; and

providing a counter electrode insulated from said conducting surface.

Claims

1. A biosensor comprising a conducting surface, a layer of dielectric material overlying the conducting surface, a plurality of micro electrodes constituted by a plurality of pores extending through the thickness of said dielectric layer, each pore being separated from its neighbour, a biopolymer positioned in said pores, and a counter electrode arranged such that electrical connection can be made between it and at least part of said conducting surface by a fluid to be assessed.

2. A biosensor according to claim 1 wherein said conducting surface comprises a carbon surface.

3. A biosensor according to claim 1 or claim 2 wherein said biopolymer is attached to said conducting surface via a linker molecule.

4. A biosensor according to claim 1 or 2 wherein the biopolymer is associated with a mediator to facilitate the transfer of electrons from said biopolymer to said conducting surface.

5. A biosensor according to claim 1 or 2 wherein said conducting surface comprises two or more areas of conducting material.

6. A biosensor according to claim 5 wherein said areas of conducting material are arranged in a substantially uniform formation.

7. A biosensor according to claim 1 wherein the biosensor is flexible.

8. A biosensor according to claim 1 further comprising means for retaining said fluid in said pores.

9. A biosensor according to claim 8 wherein said means for retaining said fluid comprises a polymer wall.

10. A biosensor according to claim 8 wherein said means for retaining said fluid comprises a layer of permeable material.

11. A biosensor according to claim 10 wherein said counter electrode comprises a perforated conducting sheet, and the layer of permeable material is between the perforated conducting sheet and the dielectric layer.

12. A biosensor according to claim 1 wherein said conducting surface and said counter electrode are arranged on a single insulating substrate.

13. A biosensor according to claim 1 wherein said counter electrode comprises a perforated conducting sheet.

14. A biosensor according to claim 1 wherein said biopolymer is an enzyme.

23. A method according to claim 15, wherein the biosensor is one as claimed in claim 1.

24. A biosensing system comprising:

a current measuring device;

a potential difference generator; and

a biosensor as claimed in claim 1 or made by the method of claim 15;

wherein said potential difference is applied by said potential difference generator between the counter electrode and the conducting surface of said biosensor and,

said current measuring device is configured to measure a current flowing between said counter electrode and said conducting surface.

15. A method of making a biosensor comprising the steps of:

providing a conducting surface;

providing a layer of dielectric material adjacent to said conducting surface, said dielectric material comprising a plurality of pores extending through the thickness of the dielectric layer;

each pore being separated from its neighbour;

providing a biopolymer in said pores; and

providing a counter electrode insulated from said conducting surface.

16. A method according to claim 15, wherein a substrate layer is provided adjacent to said conducting surface.

17. A method according to claim 15 or claim 16 further comprising the step of providing a layer of permeable material adjacent to said dielectric layer.

18. A method according to claim 17 further comprising the step of adhering said layers together.

19. A method according to claim 15, wherein the layer of dielectric material is made by applying to said conducting surface particles of substantially the same diameter as said pores;

applying a dielectric in the form of a fluid containing it to said conducting surface;

allowing said fluid to dry; and

removing said particles.

20. A method according to claim 19 wherein said particles and said fluid dielectric are premixed and are applied to said conducting substrate at the same time.

21. A method according to claim 19 or claim 20, wherein said particles are water soluble and are removed by dissolution in water.

22. A method according to claim 19 or claim 20, wherein said particles are removed by heat treatment.