Polylysine‐Catalyzed Hydrogen Evolution at Mercury Electrodes

Abstract

Abstract It has been shown that peptides and proteins produce at nanomolar concentrations a structure‐sensitive chronopotentiometric peak H at mercury electrodes, which is due to the catalytic hydrogen evolution reaction (HER). Herein, we use for the first time poly(amino acids) to obtain information about the role of individual amino acid residues in the HER. At pH 6 polylysine (polyLys) and polyarginine,tryptophan yield a peak H, in agreement with their ionization state, while polyglutamic acid gives no catalytic response. PolyLys catalyzes hydrogen evolution in its adsorbed state. Even at potentials negative to the potential of zero charge, hydrophobic interactions could be involved in polyLys adsorption.