In operando assessment of H₂O₂ production by a multicopper oxidase under direct electron transfer with a gold electrode

Abstract

A deeper understanding of the intricate redox processes at biotic/abiotic interfaces requires advanced analytical tools. We present the localized and real-time characterization of a multicopper oxidase adsorbed on a gold electrode using a dedicated microbiosensor, providing detailed and spatially resolved information. Enzymatic O₂ reduction is shown to proceed without detectable H₂O₂ accumulation. Instead, H₂O₂ originates from direct O₂ conversion at the gold surface.