▎ 摘　　要

NOVELTY - A surface-modified material is obtained by preparing polyvinylpyrrolidone-functionalized graphene by stirring polyvinylpyrrolidone and graphene oxide to secondary water, adding aqueous ammonia and hydrazine hydrate, and centrifuging to form secondary polyvinylpyrrolidone-functionalized graphene black suspension, preparing polyvinylpyrrolidone-functionalized graphene-supported nickel nanoparticles composite by adding black suspension and nickel acetate to secondary water, slowly adding freshly-prepared sodium borohydride, and adding chitosan solution to composite. USE - Surface-modified material is used for electrode e.g. glassy carbon electrode used for electrochemical detection of glucose (claimed), and electrochemical sensor used in diagnosis of diabetes, clinical detection and food detection applications. ADVANTAGE - The surface-modified material having excellent stability is rapidly and economically prepared by simple method. The electrochemical sensor formed using the surface-modified material has high sensitivity, wide linear range, and excellent reproducibility. DETAILED DESCRIPTION - A surface-modified material is obtained by preparing polyvinylpyrrolidone-functionalized graphene by stirring polyvinylpyrrolidone and graphene oxide to secondary water, electromagnetic stirring for 5-20 minutes, adding aqueous ammonia with stirring, adding hydrazine hydrate, placing mixture in water bath at 40-80 degrees C for 2-4 hours, centrifuging at room temperature and 11000-13000 rpm for 15-25 minutes, removing supernatant, adding water to form secondary polyvinylpyrrolidone-functionalized graphene black suspension, preparing polyvinylpyrrolidone-functionalized graphene-supported nickel nanoparticles composite by adding polyvinylpyrrolidone-functionalized graphene suspension and nickel acetate to secondary water at room temperature, stirring for 5-20 minutes, slowly adding freshly-prepared sodium borohydride, and stirring for 20-40 minutes, and centrifuging polyvinylpyrrolidone-functionalized graphene-supported nickel nanoparticles composite at room temperature and 3000-4000 rpm for 5-10 minutes, adding 0.1-0.3 wt.% chitosan solution, and ultrasonically-processing for 10-20 minutes, to form polyvinylpyrrolidone-functionalized graphene/nickel nanoparticles/chitosan suspension. The mass ratio of graphene oxide, polyvinylpyrrolidone, ammonia, hydrazine hydrate and secondary water is 1:0.8-1.2:0.008-0.012:0.003-0.004:3000-5000. The mass ratio of polyvinylpyrrolidone-functionalized graphene, nickel acetate, sodium borohydride and secondary water is 1:20-100:10-50:8000-12000.