Fabrication and evaluation of controllable core/shell magnetic molecular imprinted polymers based on konjac glucomannan for trichlorfon

Abstract

By combining the controllable core/shell strategy with graft copolymerization of polysaccharides, controllable core/shell magnetic molecularly imprinted polymers (MIPs) based on konjac glucomannan for selective recognition and enrichment of trichlorfon were fabricated and evaluated. By varying the dose of the polymeric precursors, the shell thickness of the core/shell structure could be regulated over a wide range. The magnetic nanoparticles encapsulated by polymers still had high magnetic performance and could be easily separated by an external magnetic field. The results of adsorption experiments showed that the MIPs could specifically recognize and adsorb trichlorfon with excellent selectivity, repeatability, and stability. The adsorption isotherm of MIPs could be fitted by the Langmuir equation. In addition, magnetic MIPs have been successfully applied to the detection of trichlorfon in real samples. Eco-friendly MIPs would be particularly suitable for the enrichment and separation of pesticide residues in food samples.

Synthesis, Evaluation, and Electrochemical Detection Application of Magnetic Molecularly Imprinted Polymers for 4,4 ′ -Methylenedianiline from Food-Contact Materials

“…This made the recogni-tion sites in the MIPs accessible for the template molecules, and it took shorter time to gain adsorption equilibrium [25]. The EDS (Figure 3(d)) confirmed the presence of iron (Fe), oxygen (O), silicon (Si), and nitrogen (N) in the MIPs suggesting that the polymer shell was successfully coated on the surface of the Fe 3 O 4 @mSiO 2 carrier [7].…”

“…Molecularly imprinted polymers (MIPs) are synthetic polymers with specific recognition sites and strong binding capacities for a given template molecule [7]. MIPs can selectively recognize and absorb the target because of the existing binding sites complementary to the template molecule [8].…”

“…At early stage of the adsorption process, the concentration of target molecules in solutions was high and lots of binding sites existed on the surface of MIPs, resulting in easy and fast combination between targets and binding sites [26]. The adsorption dynamics was weakened with the reduced concentration of target molecules and available binding sites in later adsorption period, so the adsorption rate of MIPs toward targets declined until the adsorption equilibrium was reached [7].…”