▎ 摘　　要

NOVELTY - Preparing smart graphene quantum dot cluster involves weighing 4.0 g carbon fiber into a 250 mL reaction vessel, adding 135 mL /( 95% concentrated sulfuric acid and 45mL /( 65% concentrated nitric acid mixture, performing ultrasonic treatment in a normal temperature water bath for 1 hours, then heating under reflux for 24 hours in an oil bath at /( 80 degrees C temperature, then cooling the reaction mixture to room temperature, diluting with 800 mL deionized water, and then using a centrifuge with /( 6000 rotations/minute speed for 30 minutes, separating and removing the lower layer sediment, collecting the upper black liquid, treating by vacuum suction filtration, and further removing the larger particles by using a suction membrane having a pore size of /) 0.22 micron, finally obtaining the acid solution of graphene quantum dots, and then performing multiple dialysis separation and purification in deionized water. USE - Method used for preparing smart graphene quantum dot cluster as as medicine carrier for drug release in treating tumor cells (all claimed). ADVANTAGE - The method ensures smart graphene quantum dot clusters dispersed into graphene quantum dot nanoparticles under different pH conditions, preferably 5.0-7.4 pH for pH controlled release of the smart graphene quantum dot clusters allows the therapeutic drugs carried by the smart graphene quantum dot clusters to enter the tumor cells. DETAILED DESCRIPTION - Preparing smart graphene quantum dot cluster involves weighing 4.0 g carbon fiber into a 250 mL reaction vessel, adding 135 mL /( 95% concentrated sulfuric acid and 45mL /( 65% concentrated nitric acid mixture, performing ultrasonic treatment in a normal temperature water bath for 1 hours, then heating under reflux for 24 hours in an oil bath at /( 80 degrees C temperature, then cooling the reaction mixture to room temperature, diluting with 800 mL deionized water, and then using a centrifuge with /( 6000 rotations/minute speed for 30 minutes, separating and removing the lower layer sediment, collecting the upper black liquid, treating by vacuum suction filtration, and further removing the larger particles by using a suction membrane having a pore size of /) 0.22 micron, finally obtaining the acid solution of graphene quantum dots, and then performing multiple dialysis separation and purification in deionized water with a molecular weight 3500 D dialysis bag until the exudate outside the dialysis bag becomes neutral, and then evaporating dialysis residual solution at /( 60 degrees C temperature by a rotary evaporator, and crushing to obtain a dry graphene quantum dots powder. The 100 mg graphene quantum dot powder is dissolved in 8 mL deionized water, and then dialyzed in a solvent of dimethyl sulfoxide in a regenerated cellulose dialysis bag having 1000 Da molecular weight for 4 times, and dialysate is changed every 4 hours to obtain a dimethyl sulfoxide solution of graphene quantum dots. The solution of 50 mg graphene quantum dots in dimethyl sulfoxide is transferred to a one-necked flask using hexafluorophosphate benzotriazole tetramethyl uronium as a coupling agent, and 735.3 mg hexafluorophosphate benzotriazole tetramethyl uronium and 261.48 mg hydroxybenzotriazole are added to a single-mouth flask for mixing, and then 383.58 mg tert-butyl carbazate is added, stirred at room temperature for 30 minutes, and added with 400 micro-liter N,N-diisopropylethylamine to obtain a reaction mixture system solution. The reaction is then carried out at room temperature under a nitrogen gas atmosphere for 48 hours, and then the product solution after the reaction is charged into a regenerated cellulose dialysis bag having a molecular weight of 3,500 Da, and dialysis is carried out in a dimethyl sulfoxide solution for 2 days, and dialysis is changed every 8 hours to obtain a graphene quantum dots hydrazide solution. The 50 mg graphene quantum dots hydrazide solution is added with 10 times amount of graphene quantum dots powder, followed by adding 0.5 mL trifluoroacetic acid to form a reactant mixed liquid, stirring at room temperature for 24 hours, and then raising to 50 degrees C temperature for 48 hours to obtain reaction mixture solution containing the graphene quantum dots cluster product, charging with a molecular weight of 8000-10000 Da dialysis bag, repeating the dialysis for 3-4 days in deionized water, replacing dialysate every 8 hours, and finally obtaining the product.