Molecularly imprinted star polymer-modified superparamagnetic iron oxide nanoparticle for trace level sensing and separation of mancozeb

Abstract

In this study, we developed a novel and economical electrochemical sensor to detect and remove mancozeb (a pesticide) from soil and vegetable samples using superparamagnetic iron oxide nanoparticles (SPIONs) and molecularly imprinted star polymers (MISP). The imprinted star polymer was coated on the surface of the magnetic core using a surface imprinting approach. For this, first, the SPIONs were synthesized by a hydrothermal method and then coated with vinyl silane, which is used as a platform for synthesis of mancozeb-imprinted polymers (MISPs). The resulting MISPs possess specific recognition ability, high adsorption capacity, and can be easily extracted from complex matrices under an external magnetic field. The MISPs were well characterized by field emissive scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR), dynamic light scattering (DLS), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) studies. Under the carefully optimized experimental conditions, the sensor presented good electrochemical response for mancozeb in the range from 5.96 to 257.0 μg L⁻¹ and its detection limit was calculated as 0.96 μg L⁻¹ (S/N = 3). In addition, the prepared MISPs show very good adsorption capacity for mancozeb. This shows that fabricated MISPs have great potential to become a selective and sensitive approach for trace level detection as well as removal of pesticide or insecticides.