The concurrent enrichment of glycoproteins and phosphoproteins with polyoxometalate-covalent organic framework conjugate as the adsorbent

Polyoxometalates (POMs) have been explored to tailor the surface properties of substrates to satisfy the practical demands. Herein, the hydrophobicity of vinyl-containing covalent organic framework (COF) was regulated by modifying with 3-mercaptopropyltrimethoxysilane organofunctionalized tri-lacunary polyoxometalate (MPW9) through thiol-ene click reaction. The product was termed as COF-MPW9, with a specific surface area of 396 m2 g-1. The improved super hydrophilicity of COF-MPW9 provided favorable capability for the concurrent enrichment of glycoproteins and phosphoproteins. The adsorption capacities for the representative glycoprotein and phosphoprotein, i.e., immunoglobulin G (IgG) and β-casein (β-ca), were derived to be 378 mg g-1 and 740 mg g-1, respectively. Moreover, it was demonstrated that COF-MPW9 could selectively capture glycoproteins and phosphoproteins from human serum. This is potentially valuable for the ensuing study of glycoproteomics and phosphoproteomics.