Immobilization of ABTS – laccase system in silicate based electrode for biolectrocatalytic reduction of dioxygen

Voltametrically stable 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS2−) modified electrode was obtained by sol–gel processing of methyltrimethoxysilane based sol with dissolved ABTS2− together with dispersed graphite particles. Next, extracellular laccase from Cerrena unicolor was encapsulated within a thin hydrophilic tetramethoxysilane film on the top the electrode. The obtained ABTS2− modified carbon ceramic electrode exhibits stable voltammetry corresponding to the surface confined oxidation reduction process. The biocatalytic activity of this electrode is similar to that observed when ABTS2− is present in solution.