▎ 摘　　要

A simple and effective method for the preparation of amphiphilic graphene (AG) is presented under an organic solvent-free synthetic condition. The synthetic route first involves a cyclization reaction between carboxylic groups on graphene oxide and the amino groups on 5,6-diaminopyrazine-2,3-dicarbonitrile, and subsequent reduction by hydrazine. Results of UV-vis spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Raman spectroscopy have confirmed that the covalent functionalization of graphene can be achieved through the formation of imidazo[4,5-b]pyrazine on the graphene sheets. As a result, AG can be successfully dispersed in water and common organic solvents. This work successfully provides a facile and efficient way to fabricate AG and may extend the potential applications of graphene-based materials in nanoelectronic devices, polymer fillers and biological field.