Efficiency of site-specific clicked laccase-carbon nanotubes biocathodes towards O2 reduction

Solène Gentil (1, 2) , Pierre Rousselot-Pailley (3) , Ferran Sancho (4) , Viviane Robert (3) , Yasmina Mekmouche (3) , Victor Guallar (4) , Thierry Tron (3) , Alan Le Goff (5)

1 DCM - Département de Chimie Moléculaire
2 SolHyCat - Solar fuels, hydrogen and catalysis
3 ISM2 - Institut des Sciences Moléculaires de Marseille
4 Joint BSC-CRG-IRB Research Program in Computational Biology
5 DCM - BEA - Département de Chimie Moléculaire - Biosystèmes Electrochimiques et Analytiques

A maximization of a direct electron transfer (DET) between redox enzymes and electrodes can be obtained through the oriented immobilization of enzymes onto an electroactive surface. Here, we present a strategy for obtaining carbon nanotube (CNTs) based electrodes covalently modified with perfectly control-oriented fungal laccases. Modelisations of the laccase-CNT interaction and of electron conduction pathways serve as guide in choosing grafting positions. Homogeneous populations of alkyne-modified laccases are obtained via the reductive amination of a unique surface accessible lysine residue selectively engineered near either one or the other of the two copper centers in enzyme variants. Immobilization of the site-specific alkynated enzymes is achieved via copper click on azido-modified CNTs. A highly efficient reduction of O 2 at low overpotential and catalytic current densities over-3 mA cm −2 are obtained by minimizing the distance from the electrode surface to the trinuclear cluster.

Domaines: Chimie; Catalyse; Chimie inorganique; Biochimie [q-bio.BM]

Solène Gentil, Pierre Rousselot-Pailley, Ferran Sancho, Viviane Robert, Yasmina Mekmouche, et al.. Efficiency of site-specific clicked laccase-carbon nanotubes biocathodes towards O2 reduction. Chemistry - A European Journal, 2020, 26 (21), pp.4798-4804. ⟨10.1002/chem.201905234⟩. ⟨hal-02470862⟩