A hybrid gold-carbyne nanocrystals platform for light-induced crossover of redox enzyme-like activities

Abstract

Carbyne nanocrystals (CNCs), carbon materials with one-dimensional sp-hybridized atoms, have been synthesized in our lab, and these novel carbon nanomaterials exhibit unique physical and chemical properties. Here, we report that CNCs capped with gold nanoparticles (CNCs@AuNPs), a hybrid nanostructure platform, possess dual-enzyme mimetic properties of peroxidase (POD) and superoxide dismutases (SOD), catalyzing the reduction of hydrogen peroxide (H2O2) to initiate a characteristic color reaction at acidic pH and the disproportionation of O2− producing O2 and H2O2 at alkaline pH, respectively. Interestingly, upon exposure to light, AuNPs catalyze the oxidation of oxidase (OD) substrates with the involvement of CNCs. The mechanism of the catalytic process was analyzed by measurements of the produced species and electrons. These findings make CNCs@AuNPs promising enzyme mimetic candidates and expand their applications in redox catalysis, bioassays and photodynamic therapy.