A HOLE CAN SERVE AS A MICROELECTRODE

Imperfect microelectrode fabrication may lead to an undetected constriction separating the electrode proper from the bulk solution. The "lagoon" that is thereby formed has voltammetric consequences that are examined in this article. A mathematical model reveals little effect of the lagoon on the diffusion-limited steady-state current but shows that electron-transfer rate constants may be miscalculated by several orders of magnitude. The orifice separating the lagoon from the bulk electrolyte acquires some of the features of a microelectrode. Steady-state effects beneficial to analytical voltammetry may result from the presence of lagoons.