Polymeric hydrophilic ionic liquids used to modify magnetic nanoparticles for the highly selective enrichment of...

The low abundance of glycopeptides in biological samples makes it necessary to enrich them before further analysis. In this study, the polymeric hydrophilic ionic liquid-modified magnetic (Fe₃O₄@MPS@PMAC) nanoparticles were synthesized via a one-step reflux-precipitation polymerization. Owing to the excellent hydrophilicity and strong electrostatic interaction toward glycopeptides of the polymerized hydrophilic ionic liquid, [2-(methacryloyloxy) ethyl] trimethylammonium chloride (MAC), the synthesized Fe₃O₄@MPS@PMAC nanoparticles exhibited outstanding performance in glycopeptide enrichment with high detection sensitivity (10 fmol), large binding capacity (100 μg mg^-1) and satisfied enrichment recovery (approximately 82%). Furthermore, the newly developed Fe₃O₄@MPS@PMAC nanoparticles were applied for the glycopeptide enrichment of HeLa exosome proteins. A total of 1274 glycopeptides from 536 glycoproteins were identified in three replicate analyses of 50 μg of HeLa exosome proteins. These results demonstrate the potential of Fe₃O₄@MPS@PMAC nanoparticles for both glycoproteomic analysis and exosome research.