Resonance Raman evidence of immobilization of laccase on self-assembled monolayers of thiols on Ag and Au surfaces

Resonance Raman (RR) and surface-enhanced Raman scattering (SERS) spectroscopy have been used to study immobilization of laccase on self-assembled monolayers (SAMs) of thiols containing carboxylic and amino groups, deposited on silver and gold electrodes. A new, indirect way of monitoring laccase bound to the thiol-coated Ag and Au surfaces is presented. It was demonstrated that by recording the resonance Raman spectra of the colored product of the oxidation of syringaldazine (4-hydroxy-3,5-dimethoxybenzaldehydeazine) by laccase in the presence of molecular oxygen, one may easily confirm binding as well as enzymatic activity of laccase immobilized on the SAMs modified silver and gold surfaces.