Construction of magnetic covalent organic frameworks functionalized by benzoboroxole for efficient enrichment of glycoproteins in the physiological environment.

To date, the development of highly selective and efficient glycoproteins/peptides enrichment is still a challenge for mass spectrometry-based proteomic analysis. In this work, we reported a novel strategy to prepare a magnetic amide-linked covalent organic framework functionalized by benzoboroxole (denoted as Fe3O4@COF-ABB), which was then used as an adsorbent for the enrichment of glycoproteins. The physical and adsorption properties of Fe3O4@COF-ABB were fully investigated. The Fe3O4@COF-ABB presents a regular core-shell spherical structure, quick magnetic response performance, regular porosity, and multiple binding sites of phenylboronic acid. Taking advantage of these benefits, the synthesized magnetic composites exhibited a superior adsorption capacity (565.8 mg g-1) and high selectivity towards glycoprotein immunoglobulin G (IgG) under physiological state (pH 7.4). Additionally, the adsorbent Fe3O4@COF-ABB could be easily regenerated and reused 5 times with no reduction of enrichment performance. More importantly, the practical applications of Fe3O4@COF-ABB were further demonstrated by the selective adsorption of IgG from human serum. The present work represents a rational design of versatile functionalization of magnetic COFs, which demonstrates an avenue for the selective enrichment and analysis of IgG from real biological sample matrices.