Preparation of magnetic molecularly imprinted covalent organic framework for the specific adsorption and selective extraction of diosmetin from lemon peel

Novel selective magnetic molecularly imprinted covalent organic framework polymers (MMCIPs) for the selective recognition and enrichment of diosmetin were fabricated via the Schiff base reaction of amino-functionalized magnetic nanoparticles (Fe 3 O 4 -NH 2 ), diamine with different stereostructures, and triformylphloroglucinol (TFP). Various analytical techniques were utilized to systematically characterize the MMCIPs. A notable discrepancy was observed between the practical adsorption performance of MMCIPs and the functional monomer screened by computational simulation. Detailed optimization of preparation parameters was performed. The types and recognition sites of intermolecular forces, adsorption mechanism, and adsorption performances of MMCIPs were comprehensively investigated through computational simulation and various adsorption tests. The optimized MMCIPs possessed a large specific surface area (132.3 m 2 /g), satisfactory magnetic responsiveness (28.4 emu/g), and excellent recyclability over seven cycles of adsorption-desorption. Moreover, synergistic intermolecular interactions endowed the MMCIPs with outstanding adsorption performance for diosmetin (69.9 μg/mg) and specific recognition capability (imprinting factor (IF) up to 2.16). Leveraging these advantages, MMCIPs successfully enabled the selective enrichment, rapid magnetic separation, and efficient purification of diosmetin from lemon peel extract. This work offers a new fabrication strategy for the imprinted polymers with high adsorption capacity and excellent specific recognition capability