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

摘要

In 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.