▎ 摘　　要

NOVELTY - Surface cation functionalized graphene oxide material, is claimed. The graphene oxide material is prepared by carrying out condensation reaction of carboxy group on the surface of graphene oxide and amino group of imidazole molecule to obtain imidazole functionalized graphene oxide, then reacting imidazole functionalized graphene oxide and quaternary ammonium ion by introducing quaternary ammonium ions to obtain final product. USE - The surface cation functionalized graphene oxide material is useful for enrichment analysis of phosphorylated protein at pH of 7-7.7 (claimed). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing surface cation functionalized graphene oxide material, comprising performing imidazole functionalization of graphene oxide and surface cation functionalization process.