Fast route for the synthesis of decorated nanostructured magnetic molecularly imprinted polymers using an ultrasound probe

In this paper, we report for the first time a novel, simple and fast method for the synthesis of magnetic molecularly imprinted polymers (Mag-MIPs) based on high-energy ultrasound probe. Sulfamethoxazole (SMX) was used as template molecule, methacrylic acid as functional monomer, ethylene glycole dimethacrylate as crosslinking agent and magnetic nanoparticles (NPs) as the supporting core. The effects of time (5, 7.5 and 10 min) and the applied amplitude (20, 30, 40, 50 and 60%) using the ultrasound probe for the synthesis of Mag-MIPs were studied and optimized. By applying the proposed synthesis method, the US-magMIPs synthesis time was satisfactorily reduced from several hours to a few minutes (7.5 min) in a simple way. For comparison purposes, the Mag-MIP and the non imprinted polymer (MagNIP) were also synthesized employing an ultrasound bath assisted approach (2 h, 65 °C). Magnetic NPs and US-magMIPs synthesized by both ways were investigated by means of several characterization techniques such as Fourier Transform Infrared (FT-IR) spectroscopy, Scanning/Transmission electron microscopy (SEM and STEM modes), X-Ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM) and Dynamic Light Scattering (DLS). The results obtained confirms clearly the formation of magnetic NPs and their successful decoration by the imprinted polymer in both synthesis ways. The sulfonamide binding efficiency of US-magMIPs synthesized by the ultrasound probe and ultrasound bath were investigated according to the adsorption isotherm. The obtained results showed that the US-magMIP synthesized with the probe has more binding capacity compared to the one synthesized with US bath. The adsorption time was studied and both synthesized US-magMIPs reached the maximum adsorption capacity toward SMX after 1 h and the US-magMIP probe tends to have more easiness to bind SMX in less time. The selectivity studies of the synthesized US-magMIPs based on probe and bath showed a high affinity for SMX compared to its structural analogues such as sulfadiazine, sulfamerazine and sulfacetamide.