Preparation and application of magnetic molecularly imprinted nanoparticles for the selective extraction of osthole in Libanotis Buchtomensis herbal extract

In this work, novel magnetic molecularly imprinted polymers were prepared for the selective extraction of osthole from Libanotis Buchtomensis herbal extract. During the synthesis process, double bonds grafted on the surface of Fe₃O₄ nanoparticles could not only drive the temple molecules to locate onto the surface of vinyl‐functionalized magnetic nanoparticles by π–π conjugation, which makes the distribution of binding sites ordered, but also direct the occurrence of imprinting polymerization at the surface of magnetic nanoparticles by the copolymerization of vinyl terminal groups with functional monomers and cross‐linking agent. The characteristics of the resulting polymers were evaluated by transmission electron microscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy, and vibrating sample magnetometry. Adsorption kinetics, isotherms, selectivity, reproducibility, and reusability were discussed, which suggest that the obtained nanomaterials possess rapid binding kinetics, high adsorption capacity of 17.65 mg/g, and favorable selectivity for the target molecule. Satisfactory reproducibility and reusability were verified as well. Meanwhile, the resultant imprinted nanoparticles were successfully applied to selectively separate osthole from the herbal extract, which show great potential in extracting active ingredients from traditional Chinese medicine.