Adsorption Study of Cysteine, N-Acetylcysteamine, Cysteinesulfinic Acid andCysteic Acid on a Polycrystalline Gold Electrode

摘要

Capacity against potential data for the adsorption of cysteine and otherorganosulfur compounds on polycrystalline gold are reported. Cysteine, N-acetylcysteamine and cysteinesulfinic acid form monolayers on gold through the thiol group, and significantly lower the interfacial capacity in the double layer region. On the other hand, cysteic acid forms multilayers under the same conditions. The surface excess of the compounds at full monolayer coverage has been estimated, and compared with the data for the adsorption of simple n-alkylthiols. It is argued that the packing of the cysteine and related compounds is more compact due to strong electrostatic interactions.