Scanning tunneling microscopy study of L-cysteine on Au(111)

The adsorption of L-cysteine on Au(111) from a perchlorate solution was studied by in-situ scanning tunneling microscopy. The potential-induced adsorption of the thiols lifts the reconstruction of Au(111) and at more positive potentials L-cysteine adopts a (√3 × √3)R30° adlayer structure. The potential-induced desorption of the adlayer 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.