Design of molecularly imprinted nanocomposite membrane for selective separation of lysozyme based on double-faced self-assembly strategy

In recent years, the combination of membranes and nanomaterials has made remarkable progress in separation of proteins. Nevertheless, the current combination methods suffer from the drawbacks of aggregation and embedding of nanomaterials, leading to a loss of membrane performance. In present work, the lysozyme molecularly imprinted nanocomposite membranes (LYZ-MINMs) with uniform and dense carboxyl functionalized mesoporous silica nanoparticles (C-MSNs) layer were successfully prepared by a double-faced self-assembly strategy for selective separation of LYZ from chicken egg white. Notably, the resulted LYZ-MINMs exhibit both promoted hydrophilicity (36.2°) and enhanced rebinding capacity (509 mg g⁻¹) by comparing with the MINMs designed with the blending method. The selectivity of LYZ-MINMs toward LYZ is improved by the sol–gel imprinting process, resulting in a satisfactory rebinding selectivity of 2.98, 3.22 and 3.45 for Cytochrome C, Bovine haemoglobin, and Ovalbumin, respectively. After ten cycles, the high regeneration rate (>90 %) demonstrates the potential of LYZ- MINMs for practical applications. In addition, the practicability of LYZ- MINMs further verified by utilizing diluted egg white. The work shows great promise for next-generation membranes for protein separation.