Electrochemical characterization of poly(acrylamide) membrane coated on a gold disk electrode in acetonitrile

The electrochemical behavior of a poly(acrylamide) (PAA) membrane electrode (ME), in which the PAA works as a membrane matrix for use in non-aqueous solutions, was investigated in acetonitrile. It was found that PAA MEs possess properties of microelectrode ensembles (MEEs). For the thin PAA membrane, the electrode behaved similar to a macroelectrode and peak-shaped voltammograms were achieved at low scan rates, while at high scan rates the electrode acted as a microelectrode and sigmoidal-shaped voltammograms were obtained. For the thick PAA membrane electrode, however, voltammograms were sigmoidal-shaped at low scan rates, and at high scan rates the voltammograms became peak-shaped again. Quantitative and semiquantitative analyses of the electrochemical response characteristics of these ensembles were conducted. The results show that the electrochemical behavior of these ensembles is in close agreement with the predictions of established microwell electrochemical theory.