A novel core@shell magnetic molecular imprinted nanoparticles for selective determination of folic acid in different food samples

Abstract

In this work, magnetic molecularly imprinted polymers (MMIPs) were synthesized and tested for the determination of folic acid (FA) in different food samples. The MMIPs were polymerized at the surface of Fe 3 O 4 @SiO 2 magnetic nanoparticles (MNPs) using acrylonitrile (functional monomer), ethylene glycol dimethacrylate (EGDMA) as cross-linking agent and azobiisobutyronitrile (AIBN) as an radical initiator. The morphological, topological and chemical characteristics of the MMIPs were investigated by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared (FTIR) techniques. The physico-chemical characterization, such as adsorption capacities and selectivity of MMIPs was investigated and compared with the respective MNIPs. The adsorption experimental data demonstrate that maximum adsorption capacity of MMIP at equilibrium was 8 mg g −1 and than the adsorption process of FA over MMIPs follows Freundlich adsorption isotherm model and pseudo-first-order reaction kinetic. For evaluation of this new proposed material, the recovery studies were carried out in spiked samples at different concentration levels and the obtained values were in the range of 95-104% for orange and for spinach the recoveries were between 99.5 and 102.5%. The relative standard deviations (RSD) for the recoveries were b0.5% for both samples. These results demonstrate that this novel MMIP material can be efficiently used for the selective extraction of folic acid from different food complex matrices.

Assessment of molecularly imprinted polymers (MIPs) in the preconcentration of disperse red 73 dye prior to photoelectrocatalytic treatment

“…3 were porous and homogeneous, exhibiting the "cauliflower clusters" appearance characteristic of other magnetic MIPs reported in the literature (Hussain et al 2016;Uzuriaga-Sánchez et al 2016). It can be seen from Fig.…”

“…In the next step, the Fe 3 O 4 @SiO 2 was modified with 3-methacryloxypropyltrimethoxysilane (MPS) by dispersing 250 mg of the Fe 3 O 4 @SiO 2 in 50 mL of anhydrous toluene containing 5 mL of MPS. The mixture was allowed to react for 12 h, under nitrogen bubbling, giving rise to the Fe 3 O 4 @SiO 2 -C=C material (Valero-Navarro et al 2011;Hussain et al 2016;Uzuriaga-Sánchez et al 2016). …”

Electrochemical sensing using magnetic molecularly imprinted polymer particles previously captured by a magneto-sensor

“…1. A -Schematics of the manufacturing of the magneto-sensor, a copper disc connector is placed on the tip of the conducting wire (1), then everything is inserted in a PVC tube (2), then the neodymium magnet is placed (3) and, finally, a thin layer of a graphite-epoxy composite is placed (4 [19][20][21][22][23] ( Fig. 5), not only larger signals were obtained with the mag-MIPs but also the mag-MIPs became saturated with much lower concentrations.…”

“…Magnetic molecular imprinting polymers (mag-MIPs) are particles where MIPs (a biomimetic material containing gaps where the aimed analyte can selectively bind) surround a metallic core that is easily susceptible to an external magnetic field [4,5]. MIPs were idealized as a synthetic alternative to biological receptors, imitating antibodies, in some ways they can be considered as biomimetic polymers.…”

Synthesis and characterization of magnetic-molecularly imprinted polymers for the HPLC-UV analysis of ametryn

“…MIPs recently evolved to magnetic MIPs (mag-MIPs), these particles improve the separation and opened a new window for analyzing compounds in complex sample matrices [24]. Among other advantages, these hybrid materials offer enhanced selectivity, durability, and the possibility of reuse [25][26][27][28][29]. Recent reviews detail the wige range of possibilities using these interesting materials [30][31][32].…”