New GO–PEI–Au–<scp>l</scp>-Cys ZIC-HILIC composites: synthesis and selective enrichment of glycopeptides

Abstract

GO-PEI-Au-L-Cys composites were synthesized via loading gold nanoparticles on a GO surface using polyethylenimine as reducing and stabilizing reagents, followed by L-cysteine immobilization through an Au-S bond. The composites were applied as a kind of novel ZIC-HILIC material to achieve highly selective enrichment of glycopeptides from biological samples.