Synthesis and characterization of magnetic molecularly imprinted polymers and application to the direct extraction of flavonoids from bamboo leaves

Molecularly imprinted polymers were employed for the purification and enrichment of flavonol glycosides and other flavonoid compounds to address the challenges of low content and structural similarity of polyphenolic flavonoids in plants, which render their separation very difficult. A magnetic molecularly imprinted polymer (MMIP) was synthesized via surface imprinting technology on Fe₃O₄@SiO₂ using vitexin as the template. Computational simulations identified methyl methacrylate (MMA) as the optimal functional monomer, with a template-to-monomer binding ratio of 1:6 and methanol as the most suitable porogen. Characterizations by TEM, XRD, VSM and FT-IR confirmed the successful synthesis of the MMIP under optimized conditions, which exhibited high adsorption capacity, rapid mass transfer and good regenerability. Binding experiments demonstrated that the MMIP had a maximum adsorption capacity of 16.1 mg/g. When directly applied to bamboo Leaves, the MMIP enabled the isolation of high-purity flavonoids, with HPLC successfully detecting six flavonoid compounds.