Electrochemical oxidation of 5‐hydroxytryptamine and 5‐hydroxyindoleacetic acid by integrated pulse linear scan voltammetry at ultrasmall gold ring electrodes

Ultrasmall gold ring electrodes have been constructed by electrodeposition of gold onto carbon ring electrodes. Electrodes thus formed show similar adsorption/desorption peaks for oxygen in H₂SO₄ solution compared to those obtained at conventional‐sized electrodes. These electrodes have been used in conjunction with linear scan voltammetry and subsequent cleaning pulses to obtain repeatable quantitative results for the electochemical oxidation of 5‐hydroxytrptamine and 5‐hydroxyindoleacetic acid. This technique involves the use of a linearly scanned applied potential, followed by a large positive potential to clean the electrode oxidatively and negative potential for electrode activation. The result of the cleaning pulses is that oxidation products of 5‐hydroxytryptamine are cleaned off the electrode and reproducible voltammograms are obtained.