Gold Nanoparticles as Electronic Bridges for Laccase-Based Biocathodes

Direct electron transfer (DET) reactions between redox enzymes and electrodes can be maximized by oriented immobilization of the enzyme molecules onto an electroactive surface modified with functionalized gold nanoparticles (AuNPs). Here, we present such strategy for obtaining a DET-based laccase (L...

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Detalles Bibliográficos
Autores: Gutiérrez-Sánchez, Cristina, Pita, Marcos, Vaz Domínguez, C., Shleev, Sergey, López de Lacey, Antonio
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/163640
Acceso en línea:http://hdl.handle.net/10261/163640
Access Level:acceso abierto
Palabra clave:Laccase
Bioelectrochemistry
Biocathode
Gold nanoparticles
Direct Electron Transfer
Descripción
Sumario:Direct electron transfer (DET) reactions between redox enzymes and electrodes can be maximized by oriented immobilization of the enzyme molecules onto an electroactive surface modified with functionalized gold nanoparticles (AuNPs). Here, we present such strategy for obtaining a DET-based laccase (Lc) cathode for O2 electroreduction at low overpotentials. The stable nanostructured enzymatic electrode is based on the step-by-step covalent attachment of AuNPs and Lc molecules to porous graphite electrodes using the diazonium salt reduction strategy. Oriented immobilization of the enzyme molecules on adequately functionalized AuNPs allows establishing very fast DET with the electrode via their Cu T1 site. The measured electrocatalytic waves of O2 reduction can be deconvoluted into two contributions. The one at lower overpotentials corresponds to immobilized Lc molecules that are efficiently wired by the AuNPs with a heterogeneous electron transfer rate constant k0 ≫ 400 s–1.