Carbohydrate Functionalization of Few-Layer Graphene through Microwave-Assisted Reaction of Perfluorophenyl Azide

The excellent physical and chemical properties of graphene make it an attractive nanomaterial and a component in high-performance nanocomposite materials. To prepare graphene-based nanocomposite materials, chemical functionalization is often necessary. Water-soluble ligands such as carbohydrates not only make the functionalized graphene compatible with aqueous media, but also introduce biorecognition, which is important for graphene to be used in biotechnology. In this study, we report the derivatization of few-layer graphene (FLG) with carbohydrates through microwave-assisted reaction of perfluorophenyl azide (PFPA). FLG was first treated with PFPA under microwave radiation. Subsequent conjugation with glycosyl amine gave carbohydrate-presenting FLG. Thermogravimetric analysis showed that microwave radiation gave a higher degree of functionalization compared to conventional heating, with higher weight losses for both PFPA and Man ligands. The carbohydrates (mannose and galactose) retained their bioactivity, as demonstrated by the lectin binding assays. Higher degree of binding toward lectins was obtained for the carbohydrate-functionalized FLG prepared by microwave radiation than the conventional heating.