▎ 摘　　要

A simple and sensitive glucose biosensor was developed based on the electrocatalysis of oxygen reduction by the graphene/palladium nanocomposite. This biosensor was prepared through the stepwise immobilization of palladium nanoparticles and glucose oxidase at a graphene modified screen-printed carbon electrode. The modification of graphene and palladium nanoparticles on the electrode surface not only accelerated the electron transfer rate greatly but also exhibited sensitive electrocatalysis of dissolved oxygen reduction. Thus it was used for the quantitative detection of glucose in a low potential range. This biosensor showed a wide linear response to the glucose concentration ranging from 0.1 to 6.5 mM with a detection limit of 0.035 mM (S/N = 3). Due to the usage of a low operating potential, some common interferences from ascorbic acid and uric acid were eliminated. In addition, this biosensor had excellent reproducibility, stability and operation convenience, thus providing great potentials for the practical applications.