Wiring Gold Nanoparticles and Redox Enzymes: ASelf-Sufficient Nanocatalyst for the Direct Oxidation of Carbohydrates with Molecular Oxygen

The development of artificial nanocatalysts, especially those incorporating the highly active biocatalysts (enzymes) present in nature, is a rapidly developing field in nanocatalysis and nanomaterials science. Dehydrogenases are exceptionally attractive, as they catalyze the oxidation of various cheap/common substrates to more expensive and desired products. However, their use in sustainable catalysis and/or their incorporation in advanced nanomaterials with catalytic functions are limited owing to one immense problem that can be formulated as a question: how can the electrons received from the oxidized substrate be removed? Here, a solution to this problem is demonstrated: we designed a unique nanomaterial composed of two redox enzymes (nonspecific glucose dehydrogenase and oxygen-reducing laccase) and gold nanoparticles. Both enzymes were wired through the gold nanoparticles (10nm) and direct electrochemical communication was achieved, allowing electron transfer from the redox center of glucose dehydrogenase to a copper center of laccase. As a result, self-sufficient nanocatalysts were synthesized and shown to oxidize various carbohydrates directly with molecular oxygen.