▎ 摘　　要

Metal oxide based nanocomposites are applied in phosphoproteomics for enrichment through the surface hydroxyl groups of metal oxides, though the role of the metal is rarely described. Using graphene as a template after modification with nickel oxide, a nanocomposite with an increased surface area is fabricated and applied to phosphopeptides. Characterisation shows a narrow size distribution of 15-20 nm, BET surface area of 179.70 m(2) g(-1) and a pore volume of 0.44 cm(3) g(-1). The graphene possesses well distributed NiO nanoparticles showing selectivity up to 1000 folds of complexity with a sensitivity as low as 1 femtomole. The G-NiO nanocomposite shows a higher selectivity towards phosphopeptides compared to TiO2, ZrO2 and NiO nanoparticles. The enrichment with the G-NiO nanocomposite is tested for biological samples like egg yolk, non-fat milk and human serum. Phosphopeptides having phosphorylations of up to 6 phosphate groups, derived from phosvitin and lipovitellin, are enriched in the egg yolk digest. Phosphopeptides characteristic of casein variants are enriched in the non-fat milk digest with a recovery of alpha S1 21.9%, alpha S2 30% and beta-casein 20%. Phosphorylated proteins are identified in human serum through the enrichment of phosphopeptides.