▎ 摘　　要

NOVELTY - Graphene ink comprises single layer of graphene sheet having Raman D/G band intensity ratio of 0.2 ID/IG and has crystalline structure, and single-layered graphene sheet that is different from reduced graphene oxide (RGO) and has single-layered sheet structure exfoliated from graphite. USE - Graphene ink used for electrode and biosensor (all claimed) for home appliances and batteries. ADVANTAGE - The graphene ink has high double-layer capacitance, excellent potential stability, and strong resistance to water film, gas and light. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) producing graphene ink which involves mixing the graphite and polymer to obtain a mixture, mixing the mixture with organic solvent to obtain a mixed solution, injecting the mixed solution into a reactor, and rotating the reactor at 1500-2500 rpm conditions to obtain a single-layer exfoliated graphene sheet, where the graphene sheet has a crystalline structure without basal plane defects, and the single-layered graphene sheet is different from reduced graphene oxide (RGO) and exfoliated from graphite which is defined as graphene having a sheet structure in the form of an exfoliated monolayer; (2) electrode comprising a substrate, and graphene ink on the substrate; and (3) biosensor comprising board; first conductive layer comprising the graphene ink on the substrate, first electrode made of a sensitive material on the first conductive layer, and second electrode spaced apart from the first electrode and comprising a second conductive layer made of a conductive material.