Self-assembled monolayers on bismuth electrodes

This communication reports about preliminary studies of self-assembled monolayers (SAMs) on bismuth bulk electrodes (BiBEs) using daunomycin and picric acid as electrochemical indicators. The cyclic voltammetric signals of these indicators decreased after the modification of the bismuth electrode with alkanethiols, indicating the formation of SAMs on bismuth. Signal decrease as well as the stability of the SAMs depends strongly upon the length of the alkanethiol. The bismuth-based SAMs were significantly more stable at negative potentials than SAMs on a gold substrate, yielding an useful potential range from -0.3 V to -1.3 V. Such highly stable SAMs could be beneficial for trace metal detection and biosensors. (C) 2006 Elsevier B.V. All rights reserved.