Direct Electron Transfer between a Site-Specific Pyrene-Modified Laccase and Carbon Nanotube/Gold Nanoparticle Supramolecular Assemblies for Bioelectrocatalytic Dioxygen Reduction

作者：Lalaoui Noemie; Rousselot Pailley Pierre; Robert Viviane; Mekmouche Yasmina; Villalonga Reynaldo; Holzinger Michael; Cosnier Serge; Tron Thierry^*; Le Goff Alan^*

来源：ACS Catalysis, 2016, 6(3): 1894-1900.

DOI：10.1021/acscatal.5b02442

• laccase
• carbon nanotubes
• dioxygen reduction
• electrocatalysis
• biofuel cells

Strategies to maximize direct electron transfer (DET) between redox enzymes and electrodes include the oriented immobilization of enzymes onto an electroactive surface. Here, we present a strategy for achieving a controlled orientation of a fungal laccase on carbon nanotube-based electrodes. A homogeneous population of pyrene-modified laccase is obtained via the reductive amination of a unique surface accessible lysine residue engineered near the T1 copper center of the enzyme. Immobilization of the site-specific functionalized enzyme is achieved either via pi-stacking of pyrene on pristine CNT electrodes or through pyrene/beta-cyclodextrin host guest interactions on beta-cyclodextrin-modified gold nanoparticles (beta-CD-AuNPs). Contrasting with unmodified and nonspecifically modified (pyrene-NHS) laccase-electrodes, an efficient DET is obtained at these nanostructured assemblies. Modeling the direct bioelectrocatalysis of dioxygen reduction reveals a heterogeneity in ET rates on MWCNT electrodes wheras beta-CD-AuNPs act as efficient electronic bridges, lowering ET rate dispersion and achieving a highly efficient reduction of O-2 at low overpotential (approximate to 80 mV) accompanied by high catalytic current densities of almost 3 mA cm(-2).

• 出版日期2016-3