▎ 摘　　要

NOVELTY - Preparing reducing agent based on graphene, involves preparing the oxidized graphite by weighing 1 g of graphite powder and 0.5 g of sodium nitrate, slowly adding 23 ml of concentrated sulfuric acid under ice-water bath and stirring for 30minutes. The temperature of the reaction system is not greater than 5 degrees C. Then 3 g of potassium permanganate is added slowly to the reaction system for 30 minutes at 10-15 degrees C and the reaction is continued for 1.5hours, and then reaction is carried out at 35 degrees C for 2 hours, and removed from the ice bath. USE - Method for preparing reducing agent based on graphene (claimed). ADVANTAGE - The method enables to prepare reducing agent based on graphene that is stable, safe and eco-friendly and satisfy biomedical application demands. The preparation method is simple and safe, with good biological compatibility. DETAILED DESCRIPTION - Preparing reducing agent based on graphene, involves preparing the oxidized graphite by weighing 1 g of graphite powder and 0.5 g of sodium nitrate, slowly adding 23 ml of concentrated sulfuric acid under ice-water bath and stirring for 30minutes. The temperature of the reaction system is not greater than 5 degrees C. Then 3 g of potassium permanganate is added slowly to the reaction system for 30 minutes at 10-15 degrees C and the reaction is continued for 1.5hours, and then reaction is carried out at 35 degrees C for 2 hours, and removed from the ice bath. Then 100 ml of ultra-pure water is slowly added, and reacting at 80 degrees C constant temperature in water bath for 30 minutes and stirring. Appropriate amount of hydrogen peroxide is slowly added to restore excess oxidant until there is no bubble generated and stirred for 30 minutes. The solution is allowed to stand and supernatant is discarded. The precipitate is washed with 5% hydrochloric acid and centrifuged for 5 minutes at 8000 rotations per minute, and then repeatedly washed and centrifuged at 18000 rotations per minute for 5 minutes until the pH becomes 7, and the sulfate is completely removed. The precipitate is vacuum dried at 60 degrees C for 48 hours to obtain intermediate oxidized graphite. The oxidized graphite is added to certain amount of ultrapure water and subjected to ultrasonic treatment for 20 minutes, at 40 kiloHertz, at a power of 100 Watt to obtain 0.1 mg/ml stable dispersion liquid of oxidative graphite that is centrifuged at 6000 rotations per minute for 5 minutes. The supernatant is added and a certain amount of L-ascorbic acid. Then, an appropriate amount of 25% aqueous ammonia is added to adjust the pH of the dispersion to a pH of 9-10. The dispersion is subjected to ultrasonic treatment for 10 minutes at 40 kiloHertz, at a power of 100 Watt and then stirred at room temperature and subjected to ultrasonic dispersion for 20 minutes. The dispersion is filtered through 0.22 mu filter and the residue is washed with ultrapure water until the pH of the filtrate is 7. The residue is collected and dried at 60 degrees C for 48 hours to obtain graphene.