Preparation of Close‐Packed Silver Nanoparticles on Graphene to Improve the Enzyme Immobilization and Electron Transfer at Electrode in Glucose/O2 Biofuel Cell

Abstract

AbstractIn this study, chemical reduced graphene‐silver nanoparticles hybrid (AgNPs@CR‐GO) with close‐packed AgNPs structure was used as a conductive matrix to adsorb enzyme and facilitate the electron transfer between immobilized enzyme and electrode. A facile route to prepare AgNPs@CR‐GO was designed involving in β‐cyclodextrin (β‐CD) as reducing and stabilizing agent. The morphologies of AgNPs were regulated and controlled by various experimental factors. To fabricate the bioelectrode, AgNPs@CR‐GO was modified on glassy carbon electrode followed by immobilization of glucose oxidase (GOx) or laccase. It was demonstrated by electrochemical testing that the electrode with close‐packed AgNPs provided high GOx loading (Γ=4.80 × 10−10 mol•cm−2) and fast electron transfer rate (ks=5.76 s−1). By employing GOx based‐electrode as anode and laccase based‐electrode as cathode, the assembled enzymatic biofuel cell exhibited a maximum power density of 77.437 μW•cm−2 and an open‐circuit voltage of 0.705 V.