▎ 摘　　要

NOVELTY - Preparing aqueous high-efficiency green light-emitting graphene quantum dot comprises (1) taking the concentrated sulfuric acid ice bath, adding graphene flakes to the concentrated sulfuric acid to expand the graphene, stirring under an ice bath, adding potassium permanganate, turning the solution from transparent to dark green, and keep stirring at 35degrees Celsius until the solution turns into a khaki viscous slurry, removing the water bath, adding ultrapure water in stages, continue to stirring at 35degrees Celsius for 2 hours, adding 30% hydrogen peroxide, stirring until the solution turns golden yellow, adding hydrochloric acid to the golden yellow solution for washing, adding distilled water to the above solution for washing, discarding the upper layer suspension, and taking the lower layer precipitate to obtain graphene oxide, (2) freeze-drying the graphene oxide precipitation to obtain a dry graphene oxide solid, and adding dimethylformamide to graphene oxide solid to form a graphene oxide suspension USE - The method is useful for preparing aqueous high-efficiency green light-emitting graphene quantum dot, which is used in cell imaging (claimed). ADVANTAGE - The graphene oxide quantum dot solid has good water solubility, good cytocompatibility and low cytotoxicity, and can reach quantum efficiency of 14.9%. DETAILED DESCRIPTION - Preparing aqueous high-efficiency green light-emitting graphene quantum dot comprises (1) taking the concentrated sulfuric acid ice bath, adding graphene flakes to the concentrated sulfuric acid to expand the graphene, stirring under an ice bath, adding potassium permanganate, turning the solution from transparent to dark green, and keep stirring at 35degrees Celsius until the solution turns into a khaki viscous slurry, removing the water bath, adding ultrapure water in stages, continue to stirring at 35degrees Celsius for 2 hours, adding 30% hydrogen peroxide, stirring until the solution turns golden yellow, adding hydrochloric acid to the golden yellow solution for washing, adding distilled water to the above solution for washing, discarding the upper layer suspension, and taking the lower layer precipitate to obtain graphene oxide, (2) freeze-drying the graphene oxide precipitation to obtain a dry graphene oxide solid, and adding dimethylformamide to the graphene oxide solid to form a graphene oxide suspension, ultrasonically processing the graphene oxide suspension using a cell disruptor, stirring the graphene oxide suspension, transferring to a polytetrafluoroethylene reaction kettle, placing in an oven at 200degrees Celsius for 12 hours for heating, naturally cooling to room temperature, filtering to obtain the graphene oxide quantum dot solution in dimethylformamide, and adding the graphene oxide quantum dot solution in dimethylformamide into a rotary evaporator to process to obtain a dry graphene oxide quantum dot solid.