Electrochemical Investigation of Thin PANI Film onto Insulating Substrate Using Scanning Electrochemical Microscopy

Electrochemical investigation of conducting polymer, polyaniline (PANI), deposited on insulating substrates was achieved. This study was performed through the reaction with a series of electrogenerated mediators at a microelectrode operating in the configuration of a scanning electrochemical microscope (SECM). The method proves to be a convenient tool for investigating redox properties of the electroactive materials onto insulating substrates and the occurrence of electron transfer within the modified substrate. The SECM results demonstrate the possibility of the regeneration of the mediator at the modified surface even if the used substrate is an insulator. The regeneration rate depends on the standard redox potential of the mediator, on the switching potential of the polymer and on its initial oxidation state. In addition, the obtained data could be analyzed through the construction of the steady state voltammograms allowing the extraction of the electrochemical properties of the thin organic layer deposited onto insulating surface.