Focused ion beam production of nanoelectrode arrays

We present a method for the production of nanoelectrodes using focussed ion beam techniques (FIB). The electrodes utilise nanometric holes milled in a silicon nitride based pasivation layer, followed by wet etching of a silicon oxide based pasivation layer, to expose an underlying gold electrode. After functionalisation using a surface assembled monolayer and an electrochemically grown polypyrrole, these gold nanoelectrodes have been tested, via cyclic voltammetry, in the detection of [Fe(CN)6]4−/3− ions. The nanoelectrodes will be used to investigate the electrical properties of nanometric biological specimen.