Recyclable and selective PVDF-based molecularly imprinted membrane combining mussel-inspired biomimetic strategy for dimethomorph elimination

The indiscriminate application and abuse of the broad-spectrum fungicide dimethomorph (DMM) not only causes serious residues on agricultural products, which indirectly endangers human health, but also directly harms aquatic organisms through the persistence of water pollution. In the present study, the integration of eco-friendly membrane technology and highly selective molecular imprinting technology was facilitated through the introduction of polydopamine (PDA) biomimetic technology, which promoted the elimination of DMM and held great significance for food safety and environmental protection. Herein, the fabrication process involved the initial preparation of PDA modification on the polyvinylidene fluoride (PVDF) membrane surface, followed by the modification of molecularly imprinted polymer (MIP) with DMM as a template molecule to obtain a specific adsorbed membrane material (PVDF@PDA@KH570@dualMIP membrane, dMIM) for DMM. The physical properties and chemical features of the developed dMIM were investigated using various characterization techniques, and the preparation parameters were optimized. Ultimately, the superior adsorption capacity (maximum capacity, 314 mu g/cm2) and adsorption selectivity of dMIM has been successfully achieved, alongside excellent reusability (number of cycles, 5 times). Moreover, in terms of practical application, the prepared dMIM demonstrated remarkable efficacy in eliminating DMM, with removal efficiencies in tap water ranging from 74.43 % to 86.12 % for three residual concentrations, and 90.71 % - 95.67 % in Panax notoginseng aqueous extracts at three material-to-liquid ratios, while had little impact on the quality of the extracts. We believe that this strategy provides a new insight into the design of novel adsorption materials for the selective elimination of DMM in environmental water and complex food matrix.