In Situ Scanning Force Microscopy and In Situ Quartz Microbalance Investigations on the Influence of the Anion Adsorption on the Electrocrystallization of Surface Layer Proteins

The first electrochemical in situ scanning force microscopy and time-resolved in situ electrochemical quartz microbalance investigations prove that the formation of a crystalline protein monolayer of Lysinibacillus sphaericus CCM2177 on gold is only possible when solvated hydroxide and perchlorate in the outer Helmholtz plane can be replaced by the protein carboxylate functions. Under electrochemical conditions of specific adsorption of perchlorate, however, its replacement by the protein is inhibited, and the electrochemical oxidation of amino acids together with protein denaturation takes place leading to a chaotic deposition of protein multilayers.