Bidirectional molecularly imprinted membranes for selective recognition and separation of pyrimethamine: A double-faced loading strategy

Molecularly imprinted membranes (MIMs) inspired from biological semi-permeable membranes are playing promising roles in molecularly selective recognition and separation due to its remarkable and customizable selectivity. In this research, the bidirectional pyrimethamine molecularly imprinted membranes (PMIMs) have been fabricated for selective separation of pyrimethamine (PMM). PMM was selected as the target resulting from the potential threat to human health and reusable value in aquaculture industry. The carbon nanotubes double-faced loading strategy was implemented based on polydopamine and kappa-carrageenan for the improvement of effective platform. By photo-initiated click chemistry, specific recognition sites were facilely and efficiently formed on membranes using methacrylic acid as functional monomers. Notably, results indicated that the PMIMs possess desirable rebinding selectivity (alpha = 3.24, 3.53 and 3.78) and permselectivity (beta = 3.99, 4.03 and 4.21) towards PMM despite the interference of competitors or analogues (sulfadiazine, diaveridine, and bisphenol A). High regeneration rate (>90% after ten cycles of regeneration) proved the potentials of PMIMs for practical applications. During the designed bidirectional filtration, the PMIMs showed a stable performance in separation of PMM from practical samples. The PMIMs and preparation strategy developed here will provide significant potentials for selective separation and extraction of harmful or reusable constituents form wastewater.