RESUMO
In this paper we present a simple method allowing for stable laccase immobilization on various conducting surfaces that retains the activity of the enzyme. The strategy for laccase immobilization presented in this paper relies on Zr(4+) ion coordination chemistry that involves -COO- terminal groups present on the protein. Using a host of techniques, including surface plasmon resonance (SPR), quartz crystal microbalance (QCM) gravimetry, atomic force microscopy (AFM), surface enhanced Raman scattering (SERS), resonance Raman scattering (RR) and electrochemical techniques, we show that laccase bound to a surface coordinatively through zirconium phosphonate/carboxylate (ZPC) functionalities forms a stable enzymatic layer with the enzyme retaining its activity to a significant extent.
Assuntos
Enzimas Imobilizadas/química , Ouro/química , Lacase/química , Compostos Organometálicos/química , Prata/química , Compostos de Estanho/química , Zircônio/química , Ácidos Carboxílicos/química , Eletroquímica , Microscopia de Força Atômica , Organofosfonatos/química , Quartzo/química , Reprodutibilidade dos Testes , Análise Espectral RamanRESUMO
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.
