Constructing coral reef-like imprinted structure on molecularly imprinted nanocomposite membranes based on nanospheres with hydrophilic multicores for selective separation of acteoside.

Molecularly imprinted nanocomposite membranes (MINMs) have shown great superiority in selective separation of acteoside (ACT) from phenylethanoid glycosides in Cistanche tubulosa. Herein, ACT-based MINMs (A-MINMs) with coral reef-like imprinted structure were proposed and developed for specifically separating ACT molecules. The nanospheres with hydrophilic multicores (NHMs) were introduced into polyvinylidene fluoride (PVDF) powders to obtain NHMs@PVDF membranes by a phase inversion method. Subsequently, the designed coral reef-like imprinted structure was constructed on NHMs@PVDF membrane-based surface. The A-MINMs with coral reef-like imprinted structure had dendritic and porous properties, which helped to form abundant ACT-imprinted cavities and sites of A-MINMs. In addition, the hydrophilic multicores and void space of NHMs together formed the affinity capture cages for hydrophilic ACT, enhancing rebinding capacity and permselectivity of A-MINMs. Therefore, A-MINMs with coral reef-like imprinted structure exhibited the high rebinding capacity (110.95 mg/g), rebinding selectivity of 5.15 and outstanding permselectivity of 10.04 toward ACT molecules. Moreover, the designed strategy of A-MHIMs with coral reef-like imprinted structure provides a new feasible method for permselectivity separation of other bioactive components.