Water-compatible temperature and magnetic dual-responsive molecularly imprinted polymers for recognition and extraction of bisphenol A

Abstract

Versatile molecularly imprinted polymers (MIPs) have been widely applied to various sample matrices, however, molecular recognition in aqueous media is still difficult. Stimuli-responsive MIPs have received increasing attentions due to their unique feature that the molecular recognition is regulated by specific external stimuli. Herein, water-compatible temperature and magnetic dual-responsive MIPs (WC-TMMIPs) with hydrophilic brushes were prepared via reversible addition-fragmentation chain transfer precipitation polymerization for reversible and selective recognition and extraction of bisphenol A (BPA). Transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FT-IR) and vibrating sample magnetometry (VSM) as characterization methods were used to examine the successful synthesis of polymers, and the resultant WC-TMMIPs showed excellent thermosensitivity and simple rapid magnetic separation. Controlled adsorption and release of BPA by temperature regulation were investigated systematically, and the maximum adsorption and removal efficiency toward BPA in aqueous solutions were attained at 35 °C and 45 °C, respectively, as well as a good recoverability was exhibited with the precision less than 5% through five adsorption-desorption cycles. Phenolic structural analogs were tested and good recognition specificity for BPA was displayed. Accordingly, the WC-TMMIPs were employed as adsorbents for magnetic solid-phase extraction (MSPE) and packed SPE of BPA from seawater samples. Using the two modes followed by HPLC-UV determination, excellent linearity was attained in the range of 0.1-14.5 μM and 1.3-125 nM, with low detection limits of 0.02 μM and 0.18 nM, respectively. Satisfactory recoveries for spiked seawater samples were achieved ranging from 86.3-103.5% and 96.2-104.3% with RSD within 2.12-4.33%. The intelligent WC-TMMIPs combining water-compatibility, molecular recognition, magnetic separation, and temperature regulation proved potentially applicable for selective identification, controlled adsorption/release and high-efficiency enrichment/removal of trace targets in complicated aqueous media.

Preparation of hydrophilic molecularly imprinted solid‐phase microextraction fiber for the selective removal and extraction of trace tetracyclines residues in animal derived foods

“…The result was illustrated in Figure 2, with the increase of methanol in solvent, the adsorbed TC amount decreased significantly, and also showed poor extraction performance in methanol and acetonitrile, the maximum adsorption capacity was obtained in aqueous solution. The result was consistent with previous reports [33–35], further indicated our homemade MIP‐SPME fiber is a green and environmental friendly sample pretreatment method.…”

Preparation and Characterization of Thermal and pH Dual Sensitive Hydrogel Based on 1,3‐Dipole Cycloaddition Reaction

“…In addition, 4‐VP and NIPA were chosen to, respectively, endow the pH sensitivity and thermal sensitivity to the polymers. Poly(NIPA) is one of the widely used thermosensitive polymers which presents a lower critical solution temperature (LCST) close to that of the human body (32°C–33°C) in aqueous solution [45, 46]. Below the LCST, poly(NIPA) is hydrophilic and displays a coil conformation.…”

Synthesis of molecularly imprinted polymer adsorbents for solid‐phase extraction of strobilurin fungicides from agricultural products

“…MIPs are obtained by a copolymerization process in porogen solvent with template molecule, functional monomer, and cross‐linking agent [16–18]. Due to well‐known unique advantages of good stability, high selectivity, low cost, and ease in preparation [19–21], MIPs have been widely used in SPE process for different trace pesticide residues such as organophosphorus pesticides [22–24], imidazole fungicides [25], organochlorine fungicides [26], iprodione fungicides [27], triazole pesticides [28], phenoxyacetic acid fungicides [29], benzimidazole fungicide [30], and pyrethroids insecticides [31,32]. Those reported applications have illustrated that molecularly imprinted solid‐phase extraction (MISPE) showed high extracting efficiency, little matrix effect, and consuming less organic solvent [33,34].…”