Au Nanozyme Driven Cascading Catalysis in Tollens′ Reaction: An Insight of Glucose Oxidase-Like Mechanism

Graphical [Ag(NH 3 ) 2 ] + can be directly used as an electron acceptor for the oxidation of glucose by AuNPs to accelerate Tollens′ reaction, The formed Ag nanoparticles continued to act as a cascading catalyst to accelerate the reaction and indicator, which provides a possibility for the rapid colorimetric glucose detection. Au nanoparticles (NPs) have been proven to be excellent glucose oxidase (GOx) mimics, which can catalyze the electrons transform pathway from glucose to oxygen. This study confirmed AuNPs can accelerate the reaction between [Ag(NH 3 ) 2 ] + and glucose under alkaline conditions, which is also known as the Tollens′ reaction, and the possible mechanism was proposed. Here, [Ag(NH 3 ) 2 ] + instead of O 2 acted directedly as an electron acceptor during glucose oxidation catalyzed by AuNPs, accompanied by hydrogen transfer. The as-synthesized Ag nanoparticles can also catalyze this process, similar to AuNPs, via a unique cascading catalysis mechanism in the Tollens′ reaction. A simple and heatless glucose colorimetric assay can be established based on the plasmonic band of AgNPs with a liner range of 0.6–22.2 μM, and the limit of detection is 0.32 μM.