Copper complex formed with pyridine rings grafted on cellulose nanofibrous membranes for highly efficient lysozyme adsorption

Abstract

The development of separation and purification materials with high adsorption performance and large processing throughput is of great importance. Regenerated cellulose nanofibers membranes (RC-NFM) with average fiber diameter 300 nm were fabricated and functionalized via grafting 4-vinyl pyridine (4-VP) on the cellulose (RC-VP) using a chemically immobilized photo-initiator. The pyridines in RC-VP form complex nanofibrous membranes with Cu(II) to form RC-VP-Cu(II) which enhances selectivity for lysozyme adsorption. The RC-VP-Cu(II) NFM showed superb static adsorption capacity of 800 mg·g−1 and a high saturated dynamic protein binding capacity of 700 mg·g−1 toward lysozyme. Besides, benefiting from its stable physical and chemical structures, after 5 cycles of reuses, RC-VP-Cu(II) still showed promising efficiency for lysozyme separation from egg-white samples with lysozyme activity 80% of a synthetic one. The successful synthesis of such intriguing and economic RC-VP-Cu(II) NFM may serve as a promising candidate for the next generation of rapid, massive, and cost-effective separation and purification of proteins.