High selectivity and anti-interference molecularly imprinted polymer based on spheroidal carbonized polymer dots for effective sulfadiazine sodium removal

Abstract

Although several methods for enhancing the selectivity of molecularly imprinted polymers (MIPs) have been reported, their effects on complex substrates remain unsatisfactory. In this study, a customised 1-vinyl-3-hydroxyethylimidazolium tetrafluoroborate ionic liquid with a vinyl double bond polymerizable unit and an F-atom recognition unit was employed as a precursor carbon source to prepare unique spherical carbonised polymer dots (CPDs-F) through an incomplete carbonisation process using the one-step hydrothermal method. Then used it as a novel functional monomer, sulfadiazine sodium (SDS), as a template to synthesize the SDS-imprinted material CPDs-F@MIP in aqueous media. The results indicated that the obtained CPDs-F@MIP exhibited excellent selectivity for the template, with an imprinting factor of up to 6.39, surpassing that of the MIPs prepared with chain functional monomers 2.12–4.76 times. The selective adsorption of the template molecule, SDS (selectivity coefficient: approximately 2.615–43.149), was not significantly influenced by the coexistence of contaminants with various structural characteristics. The maximum adsorption capacity reached 61.06 mg g−1. After at least twenty applications, the adsorption capability of CPDs-F@MIP did not decrease significantly. Finally, the prepared CPDs-F@MIP were used as solid-phase extraction adsorbents in combination with high-performance liquid chromatography, and the anti-interference ability and selective adsorption performance of CPDs-F@MIP in six actual water samples were investigated. Additionally, an accurate, reliable method for detecting SDS in environmental water was established (limit of detection of 0.2 μg L−1, and the recoveries ranged from 91.79% to 111.32%). Imprinting materials prepared using spherical functional monomers significantly enhance their selective recognition ability in complex media and provide new ideas for the preparation and application of novelty imprinting materials with superior performance.