SCANNING-TUNNELING-MICROSCOPY STUDY OF L-CYSTEINE AN AU(111)

The adsorption of L-cysteine on Au(lll) from a perchlorate solution wa s studied by in-situ scanning tunneling microscopy. The potential-indu ced adsorption of the thiols lifts the reconstruction of Au(111) and a t more positive potentials L-cysteine adopts a (root 3 x root 3)R30 de grees adlayer structure. The potential-induced desorption of the adlay er does not cause the reconstruction to reappear but instead leaves a roughened surface with a large number of monoatomic high gold islands and monoatomic deep holes.