▎ 摘　　要

NOVELTY - A material comprises a graphene derivative comprising a graphene core and a first pendant group, the first pendant group comprises a metal ion, a nanoparticle, a sulfonate group, an amine group, a quaternary ammonium group, or a chelating group. USE - The material is useful for preparing chromatography column for isolating protein from sample, and for preparing graphene oxide (all claimed). ADVANTAGE - The material provides unique electronic and optical properties. Additionally, the chromatographic stationary phase materials made from certain graphene derivatives exhibit superior performance in protein isolation compared to conventional stationary phase materials. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are: (1) a material, comprising a graphene derivative comprising a graphene core and a protein covalently bonded to the graphene core; (2) a chromatography column, comprising the material; (3) a chromatographic system, comprising the chromatography column; (4) a method of isolating a protein from a sample, comprising disposing the sample in a dispersion comprising the material, thus binding the protein to the material to form a protein-bound material; isolating the protein-bound material; and recovering the protein from the protein-bound material; and (5) a method of preparing graphene oxide, comprising reacting graphite sequentially with an oxidizing acid and an oxidant to form an oxidized graphene; washing the oxidized graphene with an aqueous solvent; and treating the oxidized graphene with a solution containing an intercalant to form graphene oxide.