Programmed potential sweep voltammetry for lower detection limits

Abstract

We report a novel programmed potential sweep voltammetry for a much lower detection limit than those achieved by any other known electroanalyitcal techniques. In this technique, an input waveform is programmed such that the background current would become flat or any other predefined form in the potential region of interest where the peak current arising from the analyte is observed, followed by the amplification of the background subtracted peak current. The current thus obtained showed a much better signal integrity at very low. analyte concentrations than those obtained by the traditional linear sweep voltammetric and other related voltammetric techniques. The technique was applied to the analysis of dopamine at a carbon ultramicroelectrode (10-mu m diameter). The background-compensated currents showed excellent dynamic linearity for dopamine concentrations of more than 3 orders of magnitudes between 500 pM and 100 nM with an estimated detection limit of 127 pM. This method can provide a convenient way for determining biogenic amines in real time with a much higher sensitivity.