Synthesis of a hydrophilic maltose functionalized Au NP/PDA/FeO-RGO magnetic nanocomposite for the highly specific enrichment of glycopeptides

• Published in: RSC advances 2015-07, Vol.5 (73), p.5948-59416
• Main Authors: Bi, Changfen, Jiang, Ruidong, He, Xiwen, Chen, Langxing, Zhang, Yukui
• Format: Article
• Language: English
• ISSN: 2046-2069
• DOI: 10.1039/c5ra06911d

The development of methods to isolate and enrich low-abundance glycopeptides is an important prerequisite for glycoproteomics research. In this study, a hydrophilic maltose functionalized Au nanoparticle (NP)/polydopamine (PDA)/Fe 3 O 4 -reduced graphene oxide (RGO) nanocomposite has been successfully synthesized in mild conditions. The bioadhesive polydopamine film was prepared by self-polymerization on the surface of Fe 3 O 4 -graphene oxide, which not only prevents the agglomeration of the graphene sheets and enhances the specific surface area, but also facilitates the Au NP immobilization. A great number of loading Au NPs possess the highly available surface area for the immobilization of the high density of the thiol-terminated maltose via Au-S bonds. The resulting Au NP-maltose/PDA/Fe 3 O 4 -RGO nanocomposite exhibits excellent environmental stability, good biocompatibility and water dispersibility. Furthermore, the highly loaded Fe 3 O 4 NPs make the enrichment very convenient. With all of these advances, the novel Au NP-maltose/PDA/Fe 3 O 4 -RGO nanocomposite presents selective enrichment of the glycopeptides from a low concentration of horseradish peroxidase tryptic digest (0.1 ng μL −1 ). A novel approach was developed to synthesize a hydrophilic thiol-terminated maltose-functionalized Au NP/PDA/Fe 3 O 4 -RGO nanocomposite which exhibited high selectivity and detection sensitivity in the enrichment of glycopeptides from complex samples.