Adsorption of seleno-l-cystine on silver electrode surfaces investigated by surface-enhanced Raman scattering

Adsorption of seleno-l-cystine on a silver electrode surface was examined by means of surface-enhanced Raman scattering (SERS). The seleno-l-cystine appeared to be adsorbed on Ag surfaces mainly via the strong Ag–Se bonding that developed after the Se–Se breakage. On an Ag electrode with negative potentials greater than ca. 0.2 V, the co-adsorbed chloride ions appeared to leave the surface as the potential was swept toward the negative values. Spectral frequency shifts of the CH2 and CSe stretching bands supported a potential-induced adsorption change in the selenocysteine on a silver electrode depending on the applied voltage.