▎ 摘　　要

NOVELTY - Preparing a graphene biosensor involves (1) taking substrate with a graphene layer on surface as an object; (2) dropping a biomolecular solution onto a specific site on surface of the graphene layer for functionalization; (3) forming a dispersed functionalized layer on surface of graphene layer to obtain functionalized graphite vinyl composite layer; (4) replacing substrate in the functionalized graphene composite layer by a target substrate with metal electrodes; and (5) etching it to remove the area where the graphene layer is not provided with the functional layer. USE - Method for preparing a graphene biosensor. ADVANTAGE - The method prepares a graphene biosensor, which avoids reduction of success rate of functionalization after contamination of graphene during transfer and saves the dose of biomolecule. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a graphene biosensor.