Cysteine and its derivatives as chemisorbed layers on the gold electrode surface

This contribution presents our recent results in the investigation of various cysteine derivatives as chemisorbed layers on the polycrystalline gold electrode surface. The following compounds were tested: homocysteine, penicillamine, cysteinyl-glycine and glutathione. The same compounds were previously tested as facilitators in voltammetry of cytochrome c. Relevant data were obtaining by investigating the anodic desorption, the inhibition of some electrode processes and the electron transfer reaction of copper ion bound to the adsorbed compound. The results are useful for understanding the facilitator activity of each compound in direct electrochemistry of cytochrome c. At the same time, it was possible to draw some conclusion on difussionless electrochemistry of copper in connection to the properties of the surface-immobilized ligand.