Boronate Affinity Monolith for Highly Selective Enrichment of Glycopeptides and Glycoproteins

A novel boronate affinity monolith, poly(3-acrylamidophenylboronic acid-co-ethylene dimethacrylate) (AAPBA-co-EDMA), was prepared in 530 microm capillaries by a one-step in situ polymerization procedure using a pre-polymerization mixture consisting of functional monomer 3-acrylamidophenylboronic acid, cross-linker ethylene dimethacrylate, porogenic solvent methanol with added poly(ethylene glycol) 20,000 (PEG 20,000) and initiator azobisisobutyronitrile (AIBN). The preparation of the monolith was optimized by investigating the ratio of functional monomer to cross-linker and the effect of poly(ethylene glycol) molecular weight. The resulting boronate monolith was used as a sorbent for polymer monolith microextraction (PMME). Using nucleosides as the testing analyte, the extraction performance of this boronate monolith towards glycol-containing compounds was examined. Finally, the boronate monolith was applied for selective enrichment of glycopeptides and glycoproteins.