Hybrid Amyloid-Based Redox Hydrogel for Bioelectrocatalytic H2 Oxidation

Nicolas Duraffourg (1) , Maxime Leprince (1) , Serge Crouzy (2) , Olivier Hamelin (1) , Yves Usson (3) , Luca Signor (4) , Christine Cavazza (5) , Vincent Forge (6) , Luca Albertin (1)

1 BioCE - Catalyse Bioinorganique et Environnement
2 COMX - Chimie computationnelle, modélisation et rayons X
3 TIMC-BCM - Biologie Computationnelle et Modélisation
4 IBS - UMR 5075 - Institut de biologie structurale
5 BEE - BioEnergie et Environnement
6 SolHyCat - Solar fuels, hydrogen and catalysis

An artificial amyloid-based redox hydrogel was designed for mediating electron transfer between a [NiFeSe] hydrogenase and an electrode. Starting from a mutated prion-forming domain of fungal protein HET-s, a hybrid redox protein containing a single benzyl methyl viologen moiety was synthesized. This protein was able to self-assemble into structurally homogenous nanofibrils. Molecular modeling confirmed that the redox groups are aligned along the fibril axis and are tethered to its core by a long, flexible polypeptide chain that allows close encounters between the fibril-bound oxidized or reduced redox groups. Redox hydrogel films capable of immobilizing the hydrogenase under mild conditions at the surface of carbon electrodes were obtained by a simple pH jump. In this way, bioelectrodes for the electrocatalytic oxidation of H2 were fabricated that afforded catalytic current densities of up to 270 μA cm−2, with an overpotential of 0.33 V, under quiescent conditions at 45 °C.

Domaines: Polymères; Catalyse; Science des matériaux [cond-mat.mtrl-sci]; Modélisation et simulation

Nicolas Duraffourg, Maxime Leprince, Serge Crouzy, Olivier Hamelin, Yves Usson, et al.. Hybrid Amyloid-Based Redox Hydrogel for Bioelectrocatalytic H2 Oxidation. Angewandte Chemie International Edition, 2021, 60 (26), pp.14488-14497. ⟨10.1002/anie.202101700⟩. ⟨hal-03241503⟩