▎ 摘　　要

NOVELTY - An azo derivative-grafted graphene quantum dot composite material is obtained by connecting hydroxyl group on benzene ring of one side of p-aminobenzene sulfonic azobenzene with acid chloride group on acid chlorinated graphene quantum dot. USE - Azo derivative-grafted graphene quantum dot composite material is used in sensor for detection of heavy metal ion (claimed), biomedical applications, optical and electrical devices, solar cell, electronic devices, optical particulate fuel and composite system. ADVANTAGE - The azo derivative-grafted graphene quantum dot composite material has strong identifying ability of metal ions in molecular fluorescence, and excellent selectivity and stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the composite material, which involves using acid chlorinated graphene quantum dots prepared using graphene quantum dots and mixed solution of acyl chloride and organic solvent, p-aminobenzene sulfonic azobenzene and tetrahydrofuran in a mass ratio of 1:1-3:200-300, and ethanol. The acyl chloride is thionyl chloride, phosphorus trichloride, phosphorus pentachloride or phosphorus oxychloride. The organic solvent is anhydrous N,N-dimethylformamide, tetrahydrofuran, cyclohexane, benzene or toluene.