Using electrochemical methods to study the kinetics of laccase-catalyzed oxidation of phenols

Abstract

In the present work, the laccase kinetics upon the oxidation process of phenolic compounds was studied using cyclic voltammetry (CV). Several hydroxybenzoic and cinnamic acid compounds were analyzed, and the oxidation kinetics were correlated to their chemical structures. Significant differences were observed, and several structural parameters were identified as enhancers of the reaction rate. Folin–Ciocalteau, ultraviolet–visible light (UV-vis) spectrophotometry, and thin-layer chromatography (TLC) methods were also used to assess the laccase-oxidation process. The TLC results correlated well with those from the CV, while the UV-vis results do so with those from the Folin–Ciocalteau analysis. Results suggest that intermediate adducts, nondetectable by CV, Folin–Ciocalteau, UV-vis, and TLC analyses, may be formed during the oxidation process. A new approach for using bare glassy carbon electrodes to detect phenolic compounds and monitor their oxidation using laccase enzymes is presented