Synthesis of hollow molecular imprinting nanoparticles based on polyethylenimine and boronate affinity for selective extraction of ovalbumin.

The hollow MCM-48 polyethyleneimine carboxyphenylboronic acid molecularly imprinted polymers (H-MPC@MIPs) were synthesized to efficiently and selectively separate and enrich the ovalbumin (OVA) in egg white samples. Polyethyleneimine contained enough active amino groups to increase the amount of boric acid molecules modified to silica nanoparticles. Meanwhile, the materials were etched to enhance the adsorption effect. The H-MPC@MIPs exhibited a rapid adsorption equilibrium rate (within 30 min) and outstanding adsorption capacity for OVA (1334.1 mg g-1). It possessed a good reusability after 5 cycles. In addition, both the high density and the imprinting action of boric acid were essential for enhancing the identification and binding of OVA. The OVA in egg white samples was successfully selectively enriched using this method.

A boronate-affinity magnetic molecularly imprinted polymer for luteolin recognition.

In this study, 3-carboxyphenylboronic acid (CP)-functionalized amino-modified Fe3O4 (Fe3O4@NH2-CP, FNC) magnetic molecularly imprinted polymers (FNC@MIPs) were synthesized and applied for the quick identification and selective separation of luteolin (LTL). The structure and morphology were characterized in detail by Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating specimen magnetometry (VSM) methods. The FNC@MIPs had a homogeneous shape, excellent magnetic characteristics, quick binding kinetics, a high adsorption capacity, acceptable selectivity, and stable reusability. The solid-phase extraction parameters and preparation conditions were both optimized. Under optimized conditions, the maximal adsorption capacity was 14.26 mg g-1 and the imprinting factor was 3.62. Furthermore, the experimental kinetics data were best fitted with the pseudo-first-order model (R2 = 0.9877), and the Langmuir model could describe the adsorption process (R2 = 0.9979), suggesting a monolayer covering. The practical application of the sorbent for LTL detection in Lonicera japonica Thunb samples showed recoveries in the range of 84.5-108.7%. Therefore, the strategy offers a fresh avenue for the extraction and purification of LTL.