High Redox Potential Cathode Based on Laccase Covalently Attached to Gold Electrode

A new strategy for oriented covalent immobilization of Trametes hirsuta laccase on gold electrodes is presented. The strategy is based on the gold surface modification with a mixed monolayer of an aromatic diazonium salt derivative and 6-mercapto-1-hexanol for further use as scaffold for the enzyme’...

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Bibliographic Details
Authors: Pita, Marcos, Gutiérrez-Sánchez, Cristina, Olea, David, Vélez, Marisela, García Diego, Cristina, Shleev, Sergey, Fernández López, Víctor Manuel, López de Lacey, Antonio
Format: article
Publication Date:2011
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/54208
Online Access:http://hdl.handle.net/10261/54208
Access Level:Open access
Keyword:Laccase
Gold
Biocathode
Diazonium salt
Direct electron transfer
Description
Summary:A new strategy for oriented covalent immobilization of Trametes hirsuta laccase on gold electrodes is presented. The strategy is based on the gold surface modification with a mixed monolayer of an aromatic diazonium salt derivative and 6-mercapto-1-hexanol for further use as scaffold for the enzyme’s covalent linkage. This strategy offers a variety of advantages such as high stability and laccase-friendly support morphology, which turns it into a suitable metal-enzyme interface. Conditions aiming at optimum orientation for direct electron transfer (DET) via the T1 copper site were studied. Current density values up to 40 μA·cm-2 were measured for the electrocatalytic reduction of O2 in absence of redox mediators. This strategy is a big step forward in the development of laccase-modified gold electrodes for bioelectrocatalytic reduction of O2.