title: Preparation and application of silver nanoparticle-functionalized magnetic graphene oxide nanocomposites.
abstract: Although selective enrichment of glycopeptides from complex biological samples is indispensable for mass spectrometry (MS)-based glycoproteomics, it still remains a great challenge due to the low abundance of glycoproteins and suppression of non-glycopeptides. In this study, silver nanoparticle-functionalized magnetic graphene oxide nanocomposites (GO/Fe3O4/PEI/Ag) were synthesized. Silver nanoparticles were generated in situ on the surface of magnetic graphene oxide using polyethylenimine as a reducing and stabilizing agent. The resulting material was used as an adsorbent for selective enrichment of glycopeptides. GO/Fe3O4/PEI/Ag nanocomposites offered excellent enrichment ability, which was attributed to the synergistic effect of polyethylenimine and silver nanoparticles. The nanocomposites showed superior specificity for glycopeptides even when non-glycopeptides were 100 times more concentrated than glycopeptides. The nanocomposites displayed advantages including rapid adsorption (1 min), low detection limit (25 fmol), repeatability (6 times), and high recovery (77.8%). Using these nanocomposites, 91 different glycoproteins and 136 N-linked glycopeptides were identified from among 20 μg tryptic human serum proteins and this demonstrated the superior performance of the nanocomposites for glycopeptides enrichment.
authors.affiliation: National Chromatographic R. & A. Center, Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China. lihuazhang@dicp.ac.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: National Chromatographic R. & A. Center, Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China. lihuazhang@dicp.ac.cn and University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.affiliation: National Chromatographic R. & A. Center, Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China. lihuazhang@dicp.ac.cn.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: National Chromatographic R. & A. Center, Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China. lihuazhang@dicp.ac.cn.
authors.forename: Yukui
authors.initials: Y
authors.lastname: Zhang