Article ID Journal Published Year Pages File Type
869855 Biosensors and Bioelectronics 2008 7 Pages PDF
Abstract

Laccase from Trametes hirsuta basidiomycete has been covalently bound to graphite electrodes electrochemically modified with phenyl derivatives as a way to attach the enzyme molecules with an adequate orientation for direct electron transfer (DET). Current densities up to 0.5 mA/cm2 of electrocatalytic reduction of O2 to H2O were obtained in absence of redox mediators, suggesting preferential orientation of the T1 Cu centre of the laccase towards the electrode. The covalent attachment of the laccase molecules to the functionalized electrodes permitted remarkable operational stability. Moreover, O2 bioelectroreduction based on DET between the laccase and the electrode was not inhibited by chloride ions, whereas mediated bioelectrocatalysis was. In contrast, fluoride ions inhibited both direct and mediated electron transfers-based bioelectrocatalytic reduction of O2. Thus, two different modes of laccase inhibition by halides are discussed.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
Authors
, , , , , , , ,