Superparamagnetic hydrophilic molecularly imprinted nanoparticles for an efficient and selective removal of tetracycline from water

• Published in: Materials chemistry and physics 2024-10, Vol.325, p.129754, Article 129754
• Main Authors: Anaya-Castro, Felipe de Jesús, Ochoa Terán, Adrián, Tirado-Guízar, Antonio, Pavón-Hernández, Arturo Iván, Olivas-Sarabia, Amelia, Oropeza-Guzmán, Mercedes Teresita, Pina Luis, Georgina Esther
• Format: Article
• Language: English
• Subjects: Hydrophilic imprinted polymer; Magnetic nanoparticle; Surface imprinting; Tetraclycilne removal
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2024.129754

In this work, a novel superparamagnetic hydrophilic molecularly imprinted nanomaterial for the removal of tetracycline (TC) was synthesized utilizing magnetite (Fe3O4) as the magnetic core, TC as the template molecule, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and tetraethoxysilane (TEOS) as the cross-linker. Initially, Fe3O4 magnetic nanoparticles (MNP) coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. Initially, Fe3O4 MNP coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. The synthesis method for MNP@SiO2 was optimized, and DLS analysis of 10 replicates showed a nanoparticle size of 70.1 ± 5.8 nm, indicating high method reproducibility. The MNP@SiO2, as well as the imprinted (MNP@SiO2-MIP) and non-imprinted (MNP@SiO2–NIP) nanomaterials, were characterized by FTIR, TEM, VSM, XRD, DLS, Z potential, and BET analysis. The saturation magnetization (Ms) values were 43 emu/g for MNP@SiO2 and 32 emu/g for both MNP@SiO2-MIP and MNP@SiO2–NIP, confirming suitability for magnetic separation using external magnets. Batch binding experiments conducted in water and methanol assessed adsorption isotherms and binding kinetics, with data fitting the Langmuir isotherm model better than the Freundlich model. The developed MIP exhibited significant selectivity against other molecules with similar functional groups and size. In water, the adsorption capacity of the MNP@SiO2-MIP was 23 mg/g, with an imprinting factor of 2.2. Furthermore, the MIP demonstrated good regeneration performance. The material was tested on TC-spiked tap water samples, achieving 80.1 % TC removal with high reproducibility (3.2 %, n = 3). Combining hydrophilic superparamagnetic nanoparticles with molecular imprinting enhances their potential applications in environmental remediation, antibiotic purification, and drug delivery. [Display omitted] •Fe3O4@SiO2 nanoparticles were molecularly imprinted with high reproducibility.•The imprinted nanomaterial obtained Fe3O4@SiO2-MIP is superparamagnetic and hydrophilic.•Fe3O4@SiO2-MIP nanoparticles show an excellent performance in water with good selectivity.•Fe3O4@SiO2-MIP was applied to spiked TC tap water samples with high removal efficiency.•The combination of molecular imprinting on hydrophilic magnetic nanomaterial increases its application potential.