▎ 摘　　要

NOVELTY - Biosensor based on graphene field-effect transistor, comprising a silicon substrate, a silicon dioxide isolation layer, a graphene gate electrode, a hexagonal boron nitride gate oxide layer, and a graphene channel from bottom to top, where the graphene channel is provided with a source electrode and a drain electrode; the graphene channel is bonded with a specific antibody. The specific antibody is combined with the corresponding antigen, the corresponding antigen is deposited on the graphene channel so as to change the Dirac point of the graphene channel. USE - The biosensor based on graphene field-effect transistor is useful in preparing diagnosis devices. ADVANTAGE - The transistor has high detection limit, rapid response, and stable performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparation method of biosensor based on graphene field-effect transistor comprising preparing graphene/boron nitride/graphene Van der Waals heterojunction by providing graphene; hexagonal boron nitride nanosheet and single-polishing silicon oxide sheet; the graphene is attached to the silicon dioxide isolation layer to obtain the graphene gate electrode, transferring hexagonal boron nitride nanosheet to the graphene gate electrode to obtain hexagonal boron nitride gate oxide layer; transferring graphene to the hexagonal boron nitride gate oxide layer to obtain the graphene channel; obtaining the graphene/boron nitride/graphene Van der Waals heterojunction; preparing biological sensor based on graphene field-effect transistor: depositing a source electrode and a drain electrode on the graphene channel of graphene/boron nitride/graphene Van der Waals heterojunction to obtain a two-dimensional graphene field-effect tube; then carboxylating the graphene channel surface of the two-dimensional graphene field-effect tube; the graphene channel surface carboxylation of the two-dimensional graphene field-effect tube into specific antibody solution to make the graphene channel surface bonding specific antibody, to obtain the biosensor based on graphene field-effect transistor. DESCRIPTION OF DRAWING(S) - The drawing shows a structure of the biosensor based on graphene field-effect transistor