▎ 摘　　要

NOVELTY - The method for preparing a flexible biosensor based on quantum dot graphene composite film, involves: (1) putting the natural graphite in the pre-oxidation solution to react for 3-5 hours, and then using a strong oxidant to oxidize the obtained pre-oxidation, and then peeling it off to obtain graphene oxide; (2) preparing cadmium selenide quantum dots by solvothermal method, using tri-n-octylphosphine oxide, selenium powder and cadmium oxide as precursors, 1-octadecene as solvent and oleic acid as ligand, and redispersing in toluene solution after washing, and obtaining a cadmium selenide quantum dot solution with a concentration of 1-5 mg/mL; (3) preparing cadmium selenide quantum dots-reduced graphene oxide composite film on the oil-water interface by one-step reduction method, transferring to a flexible conductive substrate as the substrate, and preparing the working electrode. USE - Preparation of the flexible biosensor, which is useful in detecting uric acid and/or dopamine (claimed). ADVANTAGE - The method enables to prepare flexible biosensor that has high sensitivity, non-cross interference of dopamine, uric acid, high sensitivity and low detection limit, and improves the detection sensitivity of the sensor. DETAILED DESCRIPTION - The method for preparing a flexible biosensor based on quantum dot graphene composite film, involves: (1) putting the natural graphite in the pre-oxidation solution to react for 3-5 hours, and then using a strong oxidant to oxidize the obtained pre-oxidation, and then peeling it off to obtain graphene oxide; (2) preparing cadmium selenide quantum dots by solvothermal method, using tri-n-octylphosphine oxide, selenium powder and cadmium oxide as precursors, 1-octadecene as solvent and oleic acid as ligand, and redispersing in toluene solution after washing, and obtaining a cadmium selenide quantum dot solution with a concentration of 1-5 mg/mL; (3) preparing cadmium selenide quantum dots-reduced graphene oxide composite film on the oil-water interface by one-step reduction method, transferring to a flexible conductive substrate as the substrate, and preparing the working electrode; and (4) loading the working electrode loaded with cadmium selenide quantum dots-reduced graphene oxide composite film with the screen-printed counter electrode and reference electrode to construct a complete flexible biosensor. An INDEPENDENT CLAIM is included for the flexible biosensor based on quantum dot graphene composite film.