Nanoelectrode array for electrochemical analysis
View Patent ↗A nanoelectrode array comprises a plurality of nanoelectrodes wherein the geometric dimensions of the electrode controls the electrochemical response, and the current density is independent of time. By combining a massive array of nanoelectrodes in parallel, the current signal can be amplified while still retaining the beneficial geometric advantages of nanoelectrodes. Such nanoelectrode arrays can be used in a sensor system for rapid, non-contaminating field analysis. For example, an array of suitably functionalized nanoelectrodes can be incorporated into a small, integrated sensor system that can identify many species rapidly and simultaneously under field conditions in high-resistivity water, without the need for chemical addition to increase conductivity.
1. A nanoelectrode array, comprising:
an electrically conducting substrate,
an insulating layer on the electrically conducting substrate, thereby providing a top surface opposite the electrically conducting substrate,
a plurality of hollow pores formed through the insulating layer to provide a plurality of working nanoelectrodes, wherein each working nanoelectrode has a critical dimension and the plurality of working nanoelectrodes has a uniform inter-electrode spacing between each nanoelectrode and wherein the working nanoelectrodes are recessed from the top surface of the insulating layer, and
a conducting layer deposited on the top surface of the insulating layer to provide a counter electrode.
2. The nanoelectrode array of claim 1 , wherein the critical dimension is less than 1 micron.
3. The nanoelectrode array of claim 2 , wherein the critical dimension is less than 100 nm.
4. The nanoelectrode array of claim 1 , wherein the inter-electrode spacing is greater than 10 times the critical dimension.
5. The nanoelectrode array of claim 1 , wherein the inter-electrode spacing is less than 100 times the critical dimension.
6. The nanoelectrode array of claim 1 , wherein the plurality of working electrodes comprises a disc electrode.
7. The nanoelectrode array of claim 1 , wherein the plurality of working electrodes comprises a band electrode.
8. The nanoelectrode array of claim 1 , wherein the plurality of working electrodes forms an orderly pattern.
9. The nanoelectrode array of claim 1 , wherein the insulating layer comprises a resist polymer.
10. The nanoelectrode array of claim 1 , wherein the working nanoelectrodes are functionalized to provide selectivity for an analyte.
11. The nanoelectrode array of claim 1 , wherein the plurality of working nanoelectrodes are combined in a parallel array.
12. The nanoelectrode array of claim 1 , further comprising at least one additional independently addressable array.
13. A method for fabricating a nanoelectrode array, comprising:
depositing a positive resist layer on an electrically conducting substrate,
forming a latent image of a pore pattern in the resist layer by nanoscale lithography, and
developing the resist to provide a plurality of hollow pores through the resist layer.
14. The method of claim 13 , further comprising depositing a working electrode material in the plurality of hollow pores.
15. The method of claim 14 , wherein the depositing step comprises electroplating.
16. The method of claim 13 , further comprising depositing a counter electrode layer on the top surface of the resist.
17. The method of claim 13 , wherein the resist layer is spun-on the substrate.
18. The method of claim 13 , wherein the forming step comprising direct writing the pore pattern in the resist layer by electron beam lithography.