▎ 摘　　要

NOVELTY - Polyethyleneimine-functionalized polyethyleneimine-functionalized graphene nanopowder has a particle size of 300-350, preferably 190-250 nm in extended form and 70-80, preferably 250-290 nm in rolled form. USE - Polyethyleneimine-functionalized polyethyleneimine-functionalized graphene nanopowder used for delivering nucleic acids, such as genes or small interfering ribonucleic acid to cells including cells of difficult transfection, and gene therapy (claimed). ADVANTAGE - The polyethyleneimine-functionalized polyethyleneimine-functionalized graphene nanopowder has good ability to transfer genes to cells of difficult transfection and better gene delivery efficiency. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing polyethyleneimine-functionalized polyethyleneimine-functionalized graphene nanopowder, which involves: (A) preparing solution containing 0.5-0.7 mg/ml natural graphite; (B) mixing 3 pts. wt. prepared solution into 1 pt. wt strong acidic solution; (C) heating the resulting mixture under microwave irradiation for refluxing for 3-4 hours; (D) dispersing precipitates at 0-4 degrees C with a strong basic solution, preferably sodium hydroxide in an ultrasonic bath; (E) filtering the obtained suspension, preferably through a 0.22 mu m membrane; (F) collecting the filtrate; (G) functionalizing with polyethyleneimine in an ultrasonic bath for 30-40 minutes; and (H) conjugating graphene nanoxides with nucleic acids.