Multilevel/hierarchical nanocomposite-imprinted regenerated cellulose membranes for high-efficiency separation: a selective recognition method with Au/PDA-loaded surface

Abstract

Although many researchers have done several studies on improving the selective separation performance of membrane materials, the conceptions and applications of membrane-based molecular imprinting separation and recognition with both high permselectivity and rebinding capacity have still faced challenges. Herein, for the first time, the bioinspired polydopamine (PDA)-modified porous regenerated cellulose membrane (pRCMs) with Au-based imprinting structure was constructed for the synthesis of molecularly imprinted nanocomposite membranes (MINMs); propranolol was used as template molecule. Importantly, based on the as-constructed PDA-modified layers, abundant Au-modified particles have been uniformly distributed onto the surfaces of membranes, and Au/PDA-based structures can be used as the imprinted-initiated factors for the preparation of sandwich-like-imprinted sites by developing a two-step temperature propranolol-imprinting method. Moreover, superior rebinding capacity (76.87 mg g⁻¹) and selectivity (4.27–4.56) of MINMs has been successfully achieved; the as-prepared MINMs also showed excellent regeneration and permselectivity of propranolol (16.01–18.34) by constructing large amounts of propranolol-imprinted sites on the Au/PDA-based surface. Therefore, under optimized conditions, MINMs would finally obtain reproducible, accessible, and stable membrane-based separation system of the propranolol molecule.