Molecularly imprinted polymer functionalized magnetic Fe₃ O₄ for the highly selective extraction of triclosan

We present a facile strategy to prepare the molecularly imprinted polymers layer on the surface of Fe₃ O₄ nanoparticles with core-shell structure via sol-gel condensation for recognition and enrichment of triclosan. The Fe₃ O₄ nanoparticles were first synthesized by a solvothermal method. Then, template triclosan was self-assembled with the functional monomer 3-aminopropyltriethoxysilane on the silica-coated Fe₃ O₄ nanoparticles in the presence of ethanol and water. Finally, the molecularly imprinted polymers were formed on the surface of silica-coated Fe₃ O₄ nanoparticles to obtain the product. The morphology, magnetic susceptibility, adsorption, and recognition property of magnetic molecularly imprinted polymers were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, vibrating sample magnetometry, and re-binding experiments. The magnetic molecularly imprinted polymers showed binding sites with good accessibility, fast adsorption rate, and high adsorption capacity (218.34 μg/g) to triclosan. The selectivity of magnetic molecularly imprinted polymers was evaluated by the rebinding capability of triclosan and two other structural analogues (phenol and p-chlorophenol) in a mixed solution and good selectivity with an imprinting factor of 2.46 was obtained. The application of triclosan removal in environmental samples was demonstrated.