FABRICATION AND CHARACTERIZATION OF SELF-ASSEMBLED SPHERICAL GOLD ULTRAMICROELECTRODES

Spherical ultramicroelectrodes with diameters of 1-30 mu m have been p repared by self-assembly of Au nanoparticles and 1,9-nonanedithiol mol ecules at the tip end of glass micropipets. The electrodes were charac terized by optical and scanning electron microscopy, cyclic voltammetr y in aqueous and acetonitrile solution, and scanning electrochemical m icroscopy approach curves. A modified theory for hemispherical electro des was used to compute the approach curves, which agreed with the exp erimental results. The construction strategy represents a bottom-up ap proach to the fabrication of microspherical electrodes.