In this study, a series of imprinted poly(methacrylic acid- co -ethylene glycol dimethacrylate) nanocarriers for diclofenac and corresponding nonimprinted polymer nanocarriers have been synthesized in 4 different types of solvents by precipitation polymerization. The products were characterized by Fourier transform infrared, scanning electron microscopy, dynamic light scattering, and Brunauer-Emmett-Teller measurement. Results showed that uniformly sized molecularly imprinted polymer (MIP) nanospheres with relatively good porosity could only be obtained in acetonitrile. The effects of solvents on the recognition and release properties of polymer particles were also carefully investigated. The binding experiments indicated that MIPs prepared in acetonitrile displayed much higher binding capacity than other MIPs with a maximum binding capacity of 65.18 mg g −1 . The Scatchard analysis showed that synthetic MIPs have special recognition sites for diclofenac, while nonimprinted polymers have not. The Sips model could provide a best fit to the equilibrium data of nanocarriers over whole concentrations. The experimental data of an adsorption kinetic study were well fitted to the pseudo–second-order kinetic model, indicating the chemisorption mechanism between diclofenac and MIPs in the process of adsorption. The drug release of diclofenac from MIPs could well be described by the Ritger-Peppas model, suggesting a non-Fickian diffusion mechanism. In addition, we successfully used MIPs to extract diclofenac at low levels from fetal bovine serum.
Novel water-compatible superparamagnetic molecularly imprinted polymers (M-MIPs) were prepared by coating superparamagnetic Fe3O4 nanoparticles with MIPs in a methanol–water reaction system. The M-MIPs were used for the selective adsorption and separation of vanillin from aqueous solution. The M-MIPs were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM). Results indicated that a core–shell structure of M-MIPs was obtained by coating a layer of silica and MIPs on the surface of the Fe3O4 nanoparticles. The obtained M-MIPs possess a loose and porous structure and can be rapidly separated from the solution using a magnet. The adsorption experiments showed that the binding capacity of the M-MIPs was significantly higher than that of the superparamagnetic non-molecularly imprinted polymers (M-NIPs). Meanwhile, the adsorption of M-MIPs reached equilibrium within 100 min, and the apparent maximum adsorption quantity (Qmax) and dissociation constant (Kd) were 64.12 μmol g–1 and 58.82 μmol L–1, respectively. The Scatchard analysis showed that homogeneous binding sites were formed on the M-MIP surface. The recoveries of 83.39–95.58% were achieved when M-MIPs were used for the pre-concentration and selective separation of vanillin in spiked food samples. These results provided the possibility for the separation and enrichment of vanillin from complicated food matrices by M-MIPs.
This work has prepared a hyper-crosslinked molecularly imprinted resins (MIRs) with chloromethylated polystyrene resin as a carrier through post-crosslinked Friedel-Crafts and surface imprinting. The prepared MIRs were used for the selective separation and purification of camptothecin (CPT). The prepared MIRs are grafted with a large amount of active group phenol, which have good hydrophilicity and are favorable for application in aqueous environments. The results of Scatchard analysis and contact angle test have proved that MIRs have good adsorption capacity and excellent hydrophilicity. In addition, the results of density functional theory (DFT) analysis show that the possible interaction forces between the template molecule CPT and the functional monomer phenol are the hydrogen bonds and electrostatic attraction. Moreover, MIRs are successfully used as a solid phase extraction (SPE) adsorbent to separate and purify CPT from Camptotheca acuminata fruit. The eluent obtained by SPE is analyzed through HPLC. The detection limit for CPT is 0.23 μg mL −1 . The established method preforms high the recovery of CPT (91.2–103.4%) with relative standard deviation less than 4.5%. The reusability of MIRs adsorbent is also investigated, and the adsorption efficiency is still above 95% after being recycled five times. The study provides a feasible and efficient method for selective separate and purify CPT from complicated system.
危险品化学品经营许可证（带存储）