Self-powered ultrasensitive glucose detection based on graphene multi-heterojunctions

A highly sensitive glucose biosensor based on vertically stacked van der Waals graphene/ZnO/p-Si heterojunctions is demonstrated. Its sensing mechanism makes use of the large variation in the Fermi energy of graphene upon direct electron transfer of glucose oxidase at the presence of glucose molecules, with a film of ZnO acting as a sieve layer to block the carriers from transferring into the underlying semiconductor layer, resulting in a superb detection sensitivity.