Boronic acid functionalized hierarchical covalent organic frameworks based on sacrificial template and thiol-ene click chemistry for the enhanced enrichment of glycoproteins.

Glycoproteins are closely related to the formation and development of many diseases and even cancer, it is necessary to design and develop a method for efficient isolation and enrichment of glycoproteins in biomedical sciences, and in particular biomarker research. In this work, a strategy has been developed for the synthesis of phenylboronic acid-modified hierarchical covalent organic frameworks (COFs), which were applied to selective enrichment of glycoproteins from complex biological samples. The metastable metal-organic framework (MOF) was utilized as a sacrificial template to prepare hierarchical COFs (HCOFs) with highly interconnected macro/meso/microprous channels, and subsequently the thiol-ene click chemistry was utilized to obtain 4-mercapto-phenylboronic acid-modified HCOFs. The resulting adsorbent has a superior specific surface area (778.61 m·g), which increases the number of effective phenylboronic acid binding sites for glycoproteins and the interconnected macro/meso/microporous pores allow the biomacromolecular glycoproteins to enter the interior of the adsorbent material, making the enrichment process more efficient. The adsorbent material exhibited the highly selective properties and excellent adsorption capacity (1138 mg·g) for glycoprotein immunoglobulin G (IgG), providing a new way for efficient enrichment of glycoproteins in complex biological samples.