Unusual oxidase-mimetic catalytic performance surpassing peroxidase in amorphous CoOx: Underlying mechanism and toward a novel H2O2-related detection paradigm

Abstract

Different from crystalline cobalt oxides (Co3O4 and CoO) and most reported nanozymes, amorphous CoOx was found to exhibit better oxidase-like catalytic performance than the peroxidase one. Mechanistic investigations revealed that the introduction of H2O2 could decompose CoOx into inactive Co2+ under acidic conditions, leading to the loss of catalytic activity. With the unusual phenomenon, a proof-of-concept “turn-off” cascade system was fabricated to detect glucose colorimetrically via combining CoOx with glucose oxidase.