▎ 摘　　要

NOVELTY - Preparing polypeptide-graphene composite material by exfoliating graphite with silk fibroin peptide water phase involves preparing silk fibroin oligopeptide solution to clean silkworm cocoons, cutting into 0.5-1.5cm2, immersing in 0.5% sodium carbonate (Na2CO3) solution at a mass ratio of 0.5% at a ratio of 1:200 at a bath temperature of 100 degrees C, degumming for 30-60 minutes, filtering and washing. The degumming and filtering and washing operations are repeated 2-3 times. The silk is dried after degumming, put in a mass fraction of 50% calcium chloride (CaCl2) solution according to the amount of 1:30, and reacted in a water bath at 80-98 degrees C for 40-60 minutes. The dissolved mixed solution is dissolved at a speed of 1000-3500rpm for 15-60 minutes, the supernatant is taken into a dialysis bag with a molecular weight cut-off of 8000-14000 Dalton (Da) for dialysis for 1-2 days. USE - Method for preparing polypeptide-graphene composite material used in hydrophobic drug delivery (claimed). ADVANTAGE - The method enables to prepare polypeptide-graphene composite material, which utilizes the amphiphilic nature of silk fibroin polypeptides, exfoliates graphite to prepare graphene, and imparts hydrophobic graphene with better hydrophilicity, so that the resulting composite material is stably dispersed in an aqueous solution, and has good biocompatibility, suitable for use Hydrophobic drug delivery. DETAILED DESCRIPTION - Preparing polypeptide-graphene composite material by exfoliating graphite with silk fibroin peptide water phase involves preparing silk fibroin oligopeptide solution to clean silkworm cocoons, cutting into 0.5-1.5cm2, immersing in 0.5% sodium carbonate (Na2CO3) solution at a mass ratio of 0.5% at a ratio of 1:200 at a bath temperature of 100 degrees C, degumming for 30-60 minutes, filtering and washing. The degumming and filtering and washing operations are repeated 2-3 times. The silk is dried after degumming, put in a mass fraction of 50% calcium chloride (CaCl2) solution according to the amount of 1:30, and reacted in a water bath at 80-98 degrees C for 40-60 minutes. The dissolved mixed solution is dissolved at a speed of 1000-3500rpm for 15-60 minutes, the supernatant is taken into a dialysis bag with a molecular weight cut-off of 8000-14000 Dalton (Da) for dialysis for 1-2 days, and dialysis for 1-2 days with distilled water, put into a polyethylene glycol solution with a mass fraction of 10% to concentrate, and the concentrated silk fibroin solution is freeze-dried to obtain silk fibroin powder. The silk fibroin and alkaline protease are reacted in a water bath at 60 degrees C, and the pH value of the reaction system is maintained at 8.5 during the reaction. The enzyme is inactivated by boiling for 10-20 minutes after the reaction. The reaction system is centrifuged at 10000-15000 revolution per minute for 15-30 minutes to remove enzyme protein and incompletely hydrolyzed silk fibroin, and the supernatant is taken and concentrated to obtain crude silk fibroin product. The silk fibroin crude product and 8600U of actinomycete enzyme are mixed according to a solid-liquid ratio of 100: 1, pH 8.5, temperature is 50-60 degrees C, and enzymolysis is 60-80 minutes to obtain silk fibrolysis solution. The silk fibroin hydrolysate is dialyzed with dialysis bag with molecular weight cutoff below 1500 Dalton (Da) for 2-3 days to obtain the silk fibroin oligopeptide solution and freeze-dry at -80 degrees C to obtain silk fibroin oligopeptide powder. The silk fibroin and oligopeptide powder is dissolved in a solution adjusted to pH 8.0 with sodium hydroxide to obtain a silk fibroin oligopeptide solution of 10.0 mg/ml. The 10.0 mg/ml silk fibroin oligopeptide solution is taken and adjusted the concentration to 0.2-5.0 mg/ml silk fibroin oligomer by adding a solution adjusted with sodium hydroxide to pH 8.0. The 0.1-0.5 mg of graphite powder is weighed into a vial, and added 0.4-2.0 ml of silk fibroin oligopeptide solution with a concentration of 0.2-5.0 mg/ml to obtain an unbound silk fibroin-graphite mixture. The unbound silk fibroin-graphite mixture is put in an ultrasonic water bath at 20-30 degrees C and sonicated for more than 4 hours. The solution after the initial ultrasonic tension is transferred to a centrifuge tube to centrifuge, removed the unstripped large particles of graphite, and taken the supernatant. The supernatant is put into a new centrifuge tube, centrifuged, removed the peptide attached to graphite, removed the supernatant, retained the precipitate, and dried to obtain the polypeptide-graphene composite material.