Fabrication of Electrochemical Nanoelectrode for Sensor Application Using Focused Ion Beam Technology

The capabilities and applications of the focused ion beam (FIB) technology for detection of an electrochemical signal in nanoscale area are shown. The FIB system, enabling continuous micro- and nanofabrication within only one equipment unit, was used to produce a prototype of electrochemical nanometer-sized electrode for sensor application. Voltammetric study of electrochemically active compound (ferrocenemethanol) revealed the diffusion limiting current (12 pA), corresponding to a disc (planar) nanoelectrode with about 70 nm diameter of contact area. This size is in a good accordance with the designed contact-area (50 nm × 100 nm for width × thickness) of the FIB-produced nanoelectrode. It confirms that produced nanoelectrode is working properly in liquid solution and may enable correct measurements in nanometer-sized regions.