Current response and signal-to-noise advantage of parallel array of microband electrodes on potential-step voltammetry

The potential-step voltammetric behavior of the reduction and oxidation limiting current of hexacyanoferate ions at a parallel array of microband electrodes or, in short, a stripe electrode, has been studied experimentally with reference to their signal-to-noise advantage. Gold-stripe electrodes of different band widths, that is, electrode B (2a(0) = 30 mu m, 2b(0) = 60 mu m) and electrode C (2a(0) = 10 mu m, 2b(0) = 60 mu m), 2a(0) and 2b(0) being the width of microband and the distance between the centers of microbands (see Fig. 1), as well as a gold planar electrode of conventional size, electrode A, were examined. The voltammetric behavior was well explained by proposed theoretical equations {M. Senda, Rev. Polarogr., 51, 245 (2005)}: the voltammetric current at the stripe electrode approaches the Cottrellian current with increasing sampling time. Calibration plots were constructed for the concentration range of 2.5 similar to 15 mu M of hexacyanoferate. The slopes and intercepts of the regression line of the plots are discussed in terms of the a(0)- and b(0)-values of the stripe electrode. The signal-to-noise advantage of the stripe electrodes has been shown. The effects of the swelling and smoothness of microband electrodes are discussed.