DIAMOND MICROELECTRODES

• US 20120037505A1
• Filed: 07/25/2011
• Published: 02/16/2012
• Est. Priority Date: 08/04/2003
• Status: Active Grant

• Current Assignee: Charles Simon James Pickles, Clive Edward Hall, Li Jiang, Neil Perkins, Richard Antonius Kleijhorst
• Original Assignee: Charles Simon James Pickles, Clive Edward Hall, Li Jiang, Neil Perkins, Richard Antonius Kleijhorst
• Inventors: Pickles, Charles Simon James, Hall, Clive Edward, Jiang, Li, Perkins, Neil, Kleijhorst, Richard Antonius
• Granted Patent: US 8,491,765 B2
• Time in Patent Office: Days
• US Class Current: 204/400
• CPC Class Codes: G01N 27/308 at least partially made of carbon

Abstract

A microlectrode comprising a diamond layer formed from electrically non-conducting diamond and containing one or more pins or projections of electrically conducting diamond extending at least partially through the layer of non-conducting diamond presenting areas of electrically conducting diamond.

Claims

1. A microelectrode comprising:

a non-conducting layer formed from electrically non-conducting material presenting a planar surface;

one or more projections of electrically conducting diamond extending at least partially through the layer of non-conducting material, the one or more projections presenting one or more planar areas of electrically conducting diamond;

the one or more projections extend to the planar surface of the non-conducting layer presenting one or more planar areas of electrically conducting diamond co-planar with the planar surface of the electrically non-conducting material; and

a contact surface or surfaces on a back side of the one or more projections of electrically conducting diamond for connection to an external circuit.

5. A microelectrode according to claim 1 or 2, wherein the one or more projections of electrically conducting diamond present circular areas of electrically conducting diamond.

6. A microelectrode according to claim 1 or 2, wherein the projections of electrically conducting diamond present elongate areas of electrically conducting diamond.

7. A microelectrode according to claim 1 or 2, wherein a plurality of projections of electrically conducting diamond are provided, each projection having a contact surface on its back side to provide individual connections between each of the projections and the external circuit.

8. A microelectrode according to claim 1 or 2, wherein the one or more projections extend to a rear surface of the non-conducting layer to provide the contact surface or surfaces for connection to the external circuit.

9. A microelectrode according to claim 1 or 2, wherein the one or more projections extend only part-way towards a rear surface of the non-conducting layer and holes are formed in the rear surface of the non-conducting layer to reveal the contact surface or surfaces on the back side of the one or more projections for connection to the external circuit.

10. A microelectrode according to claim 1 or 2, wherein the one or more projections extend to a rear surface of the non-conducting layer to provide the contact surface or surfaces for connection to the external circuit and an electrically conducting layer is provided on the rear surface of the non-conducting layer for providing an electrical connection to the one or more projections.

11. A microelectrode according to claim 1 or 2, wherein a plurality of projections of electrically conducting diamond are provided, the projections providing different types of electrode.

12. A microelectrode according to claim 11, wherein the different types of electrode are differentiated by one or more of:

applied voltage;

use made by the external circuit;

electrochemical sensing chemicals used in conjunction with the electrodes;

concentration or type of dopant in the electrically conducting diamond;

geometry or size of the electrodes.

13. A microelectrode according to claim 1 or 2, wherein the electrically conducting diamond is boron doped diamond.

14. A microelectrode according to claim 1 or 2, wherein the microelectrode provides an analysis surface which is entirely formed of diamond material with the exception of said additive if present.

15. A microelectrode according to claim 1 or 2, wherein the areas of electrically conducting diamond and co-planar surfaces are smooth.

16. A microelectrode according to claim 1 or 2, wherein the areas of electrically conducting diamond and co-planar surfaces have surface roughnesses of less than 100 nmRa.

17. A microelectrode according to claim 1 or 2, wherein the electrically conducting diamond is synthetic single crystal or polycrystalline diamond.

18. A microelectrode according to claim 1 or 2, wherein the non-conducting material is synthetic single crystal or polycrystalline diamond.

19. A microelectrode according to claim 1 or 2, wherein the one or more projections have one projection that has a width in a range 2 to 200 μ

m.

20. A microelectrode according to claim 1 or 2, wherein a plurality of projections of electrically conducting diamond are provided and a ratio of a separation between projections and a width of the projections exceeds 2.5, 5, or 10.

2. A microelectrode comprising:

a non-conducting layer formed from electrically non-conducting material presenting a planar surface;

one or more projections of electrically conducting diamond extending at least partially through the layer of non-conducting material, the projection presenting planar areas of electrically conducting diamond;

the projections presenting planar areas of electrically conducting diamond recessed relative to a surface of the non-conducting layer creating a well or reservoir in that surface; and

a contact surface or surfaces on a back side of the one or more projections of electrically conducting diamond for connection to an external circuit.

3. A microelectrode according to claim 2, wherein the well or reservoir contains an additive which presents a surface co-planar with the surface in which the well or reservoir is created, said additive modifying the sensitivity or selectivity of the electrode behaviour

4. A microelectrode according to claim 3, wherein the additive is an electrochemical (bio-)chemical.