Conductivity sensor device comprising diamond film with at least one nanopore or micropore

1. A sensor device for an application selected from ion channel recordings; liquid-liquid based sensors and resistive pulse particle counting, the sensor device comprising;

at least one sensor element, the element comprising a diamond thin film substrate, a surface of which is chemically modified; and

a pore which is a nanopore or a micropore included in the substrate;

wherein the diamond thin film substrate has a templated or layered structure wherein the layered structure comprises layers of diamond of differing conductivities, and wherein the sensor device further comprises two electrodes positioned on opposite sides of the diamond thin film substrate and configured to measure a current within the pore or to measure a voltage across the pore.

2. A device according to claim 1 wherein the diamond thin film substrate has a thickness, a first face and a second face, the first face being opposite to the second face.

3. A device according to claim 1 wherein the pore has a conical, tapered, cylindrical, picture frame, etch pit of [111] facets in a [100] face of the diamond thin film substrate, or hemispherical geometry.

4. A device according to claim 1 comprising more than one pore, in an array of pores.

5. A device according to claim 4 wherein each pore is enclosed in an individual chamber and each chamber is arranged in an array format on support structures.

6. A device according to claim 1 wherein a surface of the diamond thin film substrate has been chemically modified with a treatment selected from silanisation with 3-cyanopropyldimethylchlorosilane or other silanes, ozonation, surface oxidation, surface halogenation, photochemical attachment of molecules, or a combination thereof; and/or wherein the surface of the diamond thin film substrate has a hydrophilic functionality and a hydrophobic functionality.

7. A device according to claim 6 wherein the hydrophilic functionality is on a first face of the diamond thin film substrate and the hydrophobic functionality is on a second face; and wherein a boundary between the first and second face is at a defined location with respect to the pore; and/or wherein the hydrophilic functionality comprises O-terminated surfaces and/or the hydrophobic functionality comprises H-terminated surfaces.

8. A device according to claim 1 wherein the diamond thin film substrate separates two compartments, each compartment containing electrolyte solutions.

9. A method for single molecule detection of an analyte, for the analysis of interactions between a sensor element and an analyte, or for the determination of ion transfer, the method comprising:

providing a solution containing an analyte;

providing a device including a sensor element that recognizes the analyte wherein the sensor element comprises a diamond thin film substrate and a pore which is a nanopore or a micropore included in the substrate;

contacting the device with the solution such that an exterior surface of the sensor element is immersed in the solution and an interior pore surface is contacted by the solution;

applying a voltage across the diamond thin film substrate; and

measuring a current within the pore or a voltage across the pore to determine the concentration of the analyte;

wherein the diamond thin film substrate has a templated or layered structure wherein the layered structure comprises layers of diamond of differing conductivities, and

wherein the device further comprises two electrodes positioned on opposite sides of the diamond thin film substrate and to measure the current within the pore or to measure the voltage across the pore.

10. A method according to claim 9 wherein the sensor element binds to the analyte and the binding event causes a reduction of current across the sensor element.

11. A method according to claim 9 wherein the solution comprises two immiscible liquids selected from, aqueous electrolyte solutions in contact with organic solvents containing supporting electrolyte, and aqueous electrolyte solutions in contact with ionic liquids.

12. A method according to claim 11 wherein an interface between the immiscible liquids is modified using a modifier selected from, metal nanoparticles, semiconductor nanoparticles, lipids, polymers, ionic and zwitterionic surfactants, conducting polymers, redox polymers, and combinations thereof.

13. A method according to claim 11 wherein electrochemical analysis is combined with spectroscopic measurement.