ZnO nanotetrapod network as the adsorption layer for the improvement of glucose detection via multiterminal electron-exchange

ZnO nanotetrapod electrochemical biosensor is demonstrated for the quantitative detection of an extremely small amount of glucose. The tetrapod-like ZnO nanostructures possess good electron communication and positively charged surface, where negatively charged glucose oxidase was immobilized through electrostatic interaction. The as-fabricated biosensor presented a reproducible sensitivity of 25.3 μA/mM cm2 with a low detection limit of 4 μM for glucose. The high performance is attributed to the ZnO tetrapods with multiterminal charge conduction, larger specific surface area and three-dimensional (3D) spatial network structure of their random accumulation. Our work provides a wide insight utilizing the multiterminal ZnO nanostructure as an adsorption material to construct highly sensitive and rapidly responsive biosensors.