A novel hydrophilic polymer-coated magnetic nanomaterial based on the HILIC strategy for fast separation of glycopeptides and glycosylated exosomes.

Novel hydrophilic poly(N, N-methylenebisacrylamide/1,2-epoxy-5-hexene) coated magnetic nanospheres functionalized with 2-aminopurine (denoted as FeO@poly(MBA/EH)@2AP) for enriching glycopeptides and glycosylated exosomes were successfully obtained using a simple and green method on the basis of the HILIC (hydrophilic interaction liquid chromatography) enrichment strategy. The high density of polar groups endows the material with amazing hydrophilicity, enabling the nanomaterial to successfully capture glycopeptides and glycosylated exosomes within 1 min. Meanwhile, the materials demonstrated great sensitivity (0.01 fmol/μL), good loading capability (125 μg/mg), high selectivity (BSA:HRP = 1000:1), and repeatability (more than 10 times). Besides, the material was applied in the analysis of bio-samples, a total of 290 glycosylated peptides and 184 glycosylation sites mapping to 185 glycoproteins were identified in the serum of uremic patients. Besides, 42 glycopeptides were enriched from the saliva of healthy people. At the same time, it was verified by TEM and western blot that the complete glycosylated exosomes were successfully captured from the serum of the uremic patients. All experiments have demonstrated that FeO@poly(MBA/EH)@2AP has a promising future in practical applications.