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Graphene oxide(GO),as an important precursor for preparing graphene,apart from the special layered structure with a large theoretical specific surface area,bears abundant oxide containing groups,such as hydroxyl,epoxy and carboxylic groups.The presence of functional groups not only improves the hydrophilicity of graphene oxide,but also offers reaction sites for preparing functionalized graphene oxide.Functionalized graphene oxide was demonstrated as potential materials for glycopeptides/glycoproteins enrichment.L-Cysteine functionalized graphene oxide nanocomposites(GO/PEI/Au/L-Cys)were prepared and used as a novel ZIC-HILIC material for selective enrichment of N-linked glycopeptides [1].GO/PEI/Au/L-Cys displays the advantages of excellent hydrophilicity,large surface area and high immobilized amount of L-Cysteine.GO/PEI/Au/L-Cys shows remarkable selectivity for N-linked glycopeptides even in the presence of 100 fold non-glycopeptides.By such nanocomposites,87 different glycoproteins are identified from 5 μg tryptic human serum,which is better than the commercial ZIC-HILIC material(76).A facile method to prepare a biocompatible GO-based substrate for protein immobilization was developed to overcome the drawbacks of GO.The GO was coated with hydrophilic branched polyethyleneimine(BPEI),while Concanavalin A(Con A)as a model lectin protein was employed to fabricate the functionalized composites to evaluate the feasibility of this strategy [2].The composites exhibit an extremely high binding capacity for glycoproteins(i.e.IgG 538.3 mg g-1),which are superior to other immobilized materials.Moreover,they can work well in 500-fold non-glycoprotein interference and even in complex biological samples.All these data suggest that the GO@BPEI composites will have great potential as scaffolds for proteins fully exerting their biofunctions.