Constructing bilayer-mesoporous structure in molecularly imprinted nanocomposite membranes for efficient separation of acteoside

The main active component of Cistanche tubulosa is acteoside (ACT), which is difficult to separate due to its low content. Therefore, it is important to develop an efficient method for efficient separation of ACT. Herein, the ACT-based molecularly imprinted nanocomposite membranes (A-MINMs) doped with bilayer-mesoporous carbon nanospheres (BMCNs) were fabricated for efficient separation of ACT. The designed BMCNs mixed with polyvinylidene fluoride (PVDF) powders to prepare the hybrid membranes (BMCNs@PVDF) by a phase inversion method. Then, a sol–gel method was used to synthesize the ACT-imprinted layer on the BMCNs@PVDF. The A-MINMs-400 synthesized under the given conditions demonstrated an excellent rebinding capacity of 114.94 mg/g, the brilliant permselectivity of 7.15, and the rebinding selectivity of 4.48. It mainly attributed to the following three reasons: (i) The designed BMCNs possessed a well-defined bilayer-mesoporous structure composed of the mesoporous carbon shell, interlayer void, and mesoporous carbon core. This bilayer-mesoporous structure can construct the efficient shell@void@core@void@shell pathways in A-MINMs for intercepting ACT molecules through the A-MINMs. (ii) The interlayer void structure can provide a large space for accommodating ACT molecules, thereby enhancing the rebinding capacities of A-MINMs. (iii) The introduced BMCNs nanofillers facilitated to form the abundant ACT-imprinted sites and cavities, improving the selectivity of A-MINMs for ACT. Therefore, the development and design of A-MINMs with bilayer-mesoporous nanofillers had a great potential for efficient separation of bioactive active constituents from natural products.