Optimal design of an imprinted preassembled system by quantum chemical calculations and preparation of a surface‐imprinted material for the selective removal of quinoline

In this study, we examined the rational preparation of molecularly imprinted polymers (MIPs) for the selective removal of quinoline from octane. Before the preparation, density functional theory, as one of the methods of quantum chemical calculation, was used for the simulation of a quinoline‐imprinted preassembly system. Methacrylic acid turned out to be the more suitable monomer for quinoline compared with acrylamide, and different template–monomer ratios, including 1:1, 1:2, and 1:3, were studied and are discussed. On the basis of the result of molecular simulation, quinoline‐imprinted polymers were prepared with a combination of surface imprinting and living polymerization. The prepared quinoline–MIPs were characterized and used as selective adsorbents for batch‐mode binding experiments. The fitting result of the adsorption data indicates that the adsorption kinetics and adsorption isotherms of the quinoline‐imprinted polymers fit well a pseudo‐second‐order kinetics model and the Freundlich model, respectively. A selective recognition ability was demonstrated by equilibrium binding analysis. This study will provide needful guidance and a theoretical basis for the preparation of imprinted materials in the field of industrial denitrification. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41730.     

Mixed templates molecularly imprinted solid‐phase extraction for the detection of sulfonamides in fish farming water

Highly selective molecularly imprinted polymers (MIPs) that absorb sulfonamides (SAs) are prepared using two types of SAs as mixed templates, 2‐vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. The optimum combination of the mixed templates, their adsorption effect and the imprinting mechanism are evaluated based on SPE recoveries of a family of analytes, equilibrium binding, BET surface area analysis and UV. The results indicate that the mixed templates not only optimize the cavities of the MIPs but also improve the MIPs selectivity and adsorption capacity for the target analytes in aqueous solution. Therefore, MIPs are used for the quantitative analysis of SAs in fish farming water using off‐line SPE coupled to HPLC/DAD. The recovery and RSD were 84.16–101.19 and 1.98–7.10%, respectively. Four SAs analytes were detected in four types of water samples in the range of 8.49–74.60 ng L^?1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41491.     

Surface molecularly imprinted polymer microspheres based on nano‐TiO2 for selective recognition of kaempferol

The molecular imprinting technique is a new method for preparing molecularly imprinted polymers (MIPs) with specific molecular recognition sites for certain target molecules. In this study, a novel, facile preparation method was presented, called “seed precipitation polymerization,” for the synthesis of MIPs via surface imprinting and a support matrix. In the polymerization process, kaempferol was used as the template molecule, methacrylic acid as the functional monomer, nano‐TiO₂ as the support, azodiisobutyronitrile as the initiator, and ethylene glycol dimethacrylate as the crosslinker in acetonitrile solvent. The synthesized T‐MIP and MIP were analyzed by infrared spectroscopy and scanning electron microscopy. In addition, the obtained polymers were evaluated by adsorption isotherms and dynamic curves for their selective recognition properties for kaempferol. The results show that T‐MIP shows regular spherical particles; the adsorption dynamic curves of T‐MIP show that the adsorption capacity increases with time and reaches a maximum value and then finally reaches equilibrium, and the T‐MIP exhibits a higher affinity for kaempferol than does the MIP. The adsorption follows pseudo‐second‐order kinetics, the Freundlich adsorption equation fits the experimental data well, and there is strong evidence for multiple‐layer adsorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44888.     

Preparation,characterization and adsorption performance of molecularly imprinted microspheres for erythromycin using suspension polymerization

BACKGROUND: There are few reports on erythromycin molecularly imprinted polymers (MIPs) used as HPLC stationary phase and solid phase extraction matrices. These imprinted polymers are prepared by bulk polymerization, which is tedious and time‐consuming, and they are irregular and possess poor reproducibility and low binding capacity. In this study, molecularly imprinted microspheres for erythromycin were prepared by aqueous suspension polymerization for the first time. RESULTS: Imprinted microspheres for erythromycin were prepared using suspension polymerization in which 1.5% PVA‐water solution is used as continuous phase, and chloroform solution containing erythromycin, methacrylic acid and crosslinker is used as disperse phase. The composition of disperse phase is optimized, and the optimum molar ratio of erythromycin to methacrylic acid was 1:5. Selectivity analysis revealed that the imprinted microspheres can specifically recognize erythromycin from its structure analogues. The binding mechanism between erythromycin and methacrylic acid was investigated by UV‐Vis spectrophotometry. Adsorption kinetics and the adsorption isotherm of the imprinted microspheres indicate that erythromycin can be adsorbed rapidly by the imprinted microspheres and the maximum theoretical static binding capacity is 128.6110 mg g^?1. The imprinted microspheres were used to extract erythromycin from a milk sample and a high recovery rate was obtained. CONCLUSION: Molecularly imprinted microspheres for erythromycin were uniform and possess high adsorption capacity and excellent selectivity. They are therefore a promising extraction and chromatographic media. Copyright © 2011 Society of Chemical Industry     

Influence of synthesis conditions on the production of molecularly imprinted polymers for the selective recovery of isovaleric acid from anaerobic effluents

Two molecularly imprinted polymers (MIPs) – poly(methacrylic acid‐co‐TRIM) (TRIM, trimethylolpropanetrimethacrylate) and poly(acylamide‐co‐TRIM) – were synthesized in different solvents for the selective recovery of isovaleric acid (template) generated during the anaerobic digestion process. The chemical and structural characterizations of the synthetic adsorbent were carried out by Fourier transform infrared spectroscopy, TGA and porosimetry through N₂ adsorption–desorption isotherms. The selective and adsorptive performances of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic and selectivity studies and by adsorbent reuse experiments. The poly(methacrylic acid‐co‐TRIM) synthesized with dimethyl sulfoxide:chloroform presented higher selectivity and adsorption capacity for isovaleric acid in the presence of six volatile fatty acids. The kinetic results were well adjusted to the pseudo‐nth order and intraparticle diffusion models, leading to k values of 10^?4 and 6 × 10^?5 for the best synthesis of MIPs and not‐imprinted polymers, respectively. Moreover, the Sips model best described the adsorption isotherm and generated a maximum adsorption capacity of ca 209 mg g^?1 (at 25 °C). Cycles of MIP use–desorption–reuse indicated that the selective adsorbent performed better than commercial adsorbents, losing less than 3% of adsorption capacity after three cycles. © 2018 Society of Chemical Industry     

Comparison of molecular adsorption ability of the molecularly imprinted polymers prepared by ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate as cross linkers

The target of this study was to synthesize the molecularly imprinted polymers (MIPs) of L ‐phenylalanine as the solid phases for characterization of molecular adsorption by molecularly imprinted solid phase extraction (MISPE). These MIPs, in microscale, were synthesized using thermal (40°C)‐compared with thermal (65°C)‐initiated polymerization process. Itaconic acid was chosen as the functional monomers, and either ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate (TRIM) was used as the cross linker and was compared together. The influences of several parameters on the properties of the MIPs were investigated, especially physical robustness from the percentage yields and molecular adsorption from the percentage recovery by MISPE. The best yields were obtained from polymers made using TRIM and thermal (65°C)‐initiated polymerization. However, there were no significant differences in molecular adsorption. It was concluded that these parameters can be considered to synthesize MIPs for chiral separation in advance steps such as other related chromatographic techniques. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2325–2330, 2007     

Surface molecularly imprinted polymers based on yeast prepared by atom transfer radical emulsion polymerization for selective recognition of ciprofloxacin from aqueous medium

To achieve selective recognition of water‐soluble ciprofloxacin (CIP), an effective method was developed for the preparation of surface molecularly imprinted polymers based on the yeast particles (yeast@MIPs) via atom transfer radical emulsion polymerization (ATREP). The reactions were carried out in the nontoxic and green emulsion system at room temperature, which was environment friendly with low energy consumption. In this study, the yeast, for the advantages of low cost, easily available source and abundant active groups on the cell wall, was selected as an ideal biological support substrate. The prepared yeast@MIPs was characterized by FT‐IR, SEM, TEM, EDS, and elemental analysis techniques. Batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics, selective recognition, and reuse ability of yeast@MIPs. The experimental static adsorption data of CIP on to yeast@MIPs were well‐described by Langmuir, Freundlich, and pseudo‐second‐order models. The maximum static adsorption capacity for CIP of yeast@MIPs was 18.48 mg g^?1, and the adsorption equilibrium could be reached in 60 min. The selectivity coefficients for CIP relative to enrofloxacin, tetracycline, and sulfadiazine were 1.212, 2.002, and 10.65, which demonstrated CIP of high affinity and selectivity over three competitive antibiotics. In addition, the reusability of the material without obvious deterioration (8.52% loss) in performance was observed at least four repeated cycles. And the yeast@MIPs was used to determine CIP from spiked shrimp samples by HPLC analysis. These results showed that yeast was a well‐defined substrate and ATREP was a promising technique for the preparation of surface molecularly imprinted polymers targeting templates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40310.     

Synthesis of novel photoresponsive molecularly imprinted polymer microspheres with special binding properties

An azobenzene‐containing molecularly imprinting polymer microsphere with photoresponsive binding properties toward 2,4‐dichlorophenoxyacetic acid (2,4‐D) was successful prepared via silica surface polymerization. The number‐average diameters of silica and imprinting polymer microsphere are 0.5 and 0.7 μm, respectively. The static adsorption, binding and selectivity experiments were performed to investigate the adsorption properties and recognition characteristics of the polymers for 2,4‐D. The equilibrium adsorptive experiments indicated that 2,4‐D‐SMIP(surface molecularly imprinted polymers) has significantly higher adsorption capacity for 2,4‐D than its nonimprinted polymers (SNIP).The binding constant K_d and apparent maximum number Q_max of the imprinted polymer were determined by Scatchard analysis as 0.054 mmol L^?1 and 0.167 mmol g^?1_, respectively. The result of photoregulated release and uptake of 2,4‐D experiment demonstrated that azo‐containing SMIP can make use of light and change it into mechanical properties to release and take up the template molecules. It means that the SMIP can be controlled by light. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 869‐876, 2013     

Fabrication of ordered microporous styrene‐acrylonitrile copolymer blend imprinted membranes for selective adsorption of phenol from salicylic acid using breath figure method

Highly selective, ordered microporous molecularly imprinted membranes (MIMs) for phenol were synthesized by breath figure (BF) method using styrene‐acrylonitrile copolymer (SAN) as the membrane matrix and molecularly imprinted polymer nanoparticles (nano‐MIPs) as the imprinted nanoparticles. The nano‐MIPs were synthesized by oil‐in‐water emulsion polymerization using 4‐vinyl pyridine (4‐VP), methyl methacrylate (MMA) or cinnamic acid (CA) as the functional monomer, respectively. The prepared nano‐MIPs were characterized by transmission electron microscope (TEM) and Raman, whereas MIMs were characterized by SEM, membrane flux, and selective adsorption experiments. Morphological analysis exhibited that the addition of nano‐MIPs improved the formation of ordered and well‐defined porous membrane morphology. Compared with MMA‐MIM and CA‐MIM, the 4‐VP‐MIM exhibited higher membrane flux, adsorption capacity, and stronger selective binding for phenol as well as excellent permeation selectivity for phenol. Moreover, the selective effect of 4‐VP‐MIM on phenol was strongly affected by the amount of 4‐VP imprinted nanoparticles (nano‐4‐VP‐MIPs). The experimental data revealed that the 4‐VP‐MIM containing 2.0 wt % of nano‐4‐VP‐MIPs exhibited the highest separation selectivity for the template phenol, whose selectivity coefficients for phenol relative to salicylic acid (SA) and p‐hydroxybenzoic acid (p‐HB) were 5.6770 and 5.5433, respectively, which was close to the predicted selectivity coefficient value. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42350.     

One‐pot method for obtaining hydrophilic tetracycline‐imprinted particles via precipitation polymerization in ethanol

In this study, we used a green, one‐pot method to synthesize hydrophilic molecularly imprinted polymers (MIPs) via the precipitation polymerization of hydrophilic monomers in ethanol. The as‐prepared materials were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic light scattering, and water contact angle measurements (27.3 ± 0.1°). As compared to the imprinting and nonimprinting processes, tetracycline (TC), as a template molecule, had an important effect on the morphology of the MIPs, and the possible mechanism is discussed in detail. We also discuss the effects of the parameters on the binding performance as determined by batch adsorption experiments in pure water. The adsorption capacity increased with increasing concentration and temperature at an optimum pH of 5.0. The Langmuir isotherm fitted the data better, with a maximal concentration of 45.75 μmol/g at 318 K. The kinetic properties of the MIPs (within 3.0 h) toward TC were analyzed with pseudo‐first‐order and pseudo‐second‐order kinetic equations and the intraparticle diffusion model. The MIPs exhibited specific recognition toward TC, and other competitive antibiotics were used as references. All of the results indicate that the MIPs exhibited a large adsorption capacity and great specific recognition for TC. The high affinity to TC of the MIPs, with its fast and easy fabrication, provides them with potential applications in the selective separation of the TC antibiotics from an aqueous environment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40071.     

三硝基甲苯分子印迹电化学传感器的制备和应用

以三硝基甲苯（TNT）为模板分子,甲基丙烯酸（MAA）为功能单体,采用乳液聚合法制备TNT的分子印迹聚合物（MIPs）。将制备的MIPs分散在溶剂中,通过表面涂覆法制备出检测TNT的分子印迹电化学传感器。紫外光谱表明TNT与MAA之间存在相互作用力,有助于形成结构稳定、亲和性强的MIPs。利用扫描电镜观测不同制备条件下印迹聚合物的表观形貌,发现溶剂用量为30mL、乳化剂用量为12mg时制备的聚合物形貌较优异。吸附实验表明MIPs对TNT的吸附量随着TNT初始浓度的增加而增加,140min后达到最大吸附量的95%。MIPs对TNT的分离常数远大于RDX和DNT,对RDX和DNT的选择性系数均达到4.4以上,说明MIPs对TNT有较好的选择性吸附能力。铁氰化钾探针实验和对TNT的响应曲线验证了电化学传感器的成功制备,该传感器富集3min就达到了最大电流值的94%,5min内达到吸附平衡。TNT浓度在0.1~5mg/mL的范围内与峰电流有良好的线性关系,检出限为0.06mg/mL。MIPs传感器对TNT的电流响应分别为DNT和RDX的3.13倍、3.27倍,说明其对TNT分子具有很强的特异性识别能力。     

Direct nanolayer preparation of molecularly imprinted polymers immobilized on multiwalled carbon nanotubes as a surface-recognition sites and their characterization

Molecular imprinting is a method for making artificial receptor sites in a polymer. This article reports the direct nanolayer immobilization of molecularly imprinted polymers (MIPs) on hydroxyl-functionalized multiwalled carbon nanotubes (MWCNTs) without any binder to improve their characteristics. MIPs were formed for hydrochlorothiazide (HCT) as a template on the surface of the MWCNTs with methacrylic acid (functional monomer) and ethylene glycol dimethacrylate (crosslinking agent) with a thermal polymerization technique. The morphology and stability of the immobilized molecularly imprinted polymers on the surface of multiwalled carbon nanotubes (MIPCNTs) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The resulting MIPCNTs demonstrated favorable selectivity, good stability, and a higher adsorption capacity for the template molecule (93.0 μg/mg) compared to products created by bulk polymerization. The adsorption kinetics of HCT at the surface of the MIPCNTs was in agreement with the second-order rate equation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Adsorption and selective recognition of 17?-estradiol by molecularly imprinted polymers

The 17?-estradiol-imprinted polymers using non-covalent approach with methacrylic acid as the functional monomer was prepared and characterized. The effect of porogenic solvents on the adsorption capacity and thermal stability of the molecularly imprinted polymers (MIPs) were examined. Scanning electron microscopic images showed that the synthesized MIPs were bulk porous materials. The surface areas of MIPs increased from 151?C188 to 239?C292?m²?g^-1 when templates were removed by methanol using Soxhlet extraction. In addition, the MIPs prepared in chloroform had a higher adsorption capacity towards 17?-estradiol (1,212???g?g^-1) than that in acetonitrile (769???g?g^-1), indicating that less polar porogenic solvent is suitable for synthesis of non-covalent MIPs. FTIR showed that the carbonyl group is the major functional group in MIPs to form monomer-template complex via H-bond. In addition, only a slight decrease (< 5?%) in adsorption capacity of the MIPs was observed when incubated at 80?°C for 5?h. Analysis of the capacity factor values (??_imp??) for MIPs indicated that the rebinding ability from selective recognition sites of MIPs decreased in the order 17?-estradiol?>?testosterone?>?benzo[a]pyrene?>?progesterone?>?phenol, and the ??_imp?? values decreased from 2.68 to 0.63, indicating the excellent selectivity of MIPs among closely related compounds. Results obtained in this study clearly indicate that the imprinted polymer is specific for recognizing 17?-estradiol. The excellent selectivity and high adsorption capacity of 17?-estradiol-imprinted polymers open the door to develop MIPs for effective separation and adsorption of estrogenic compounds.     

Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix

The present work continues the previous studies concerning the synthesis and characterization of molecularly imprinted polymers (MIPs) with sclareol as template and three poly(acrylonitrile‐co‐acrylic acid) (AN:AA) copolymers with different ratios between monomers as matrices. The previous studies of rheology, elemental analysis, infrared spectroscopy, size exclusion chromatography, thermogravimetry, differential scanning calorimetry, batch rebinding tests, and Scatchard analysis, which confirmed the molecular imprinting, are being completed with the current equilibrium and kinetic adsorption studies. For this purpose, eight adsorption isotherms and three kinetic adsorption models were applied to six sets of experimental data obtained after three sclareol‐imprinted adsorbents (MIPs) and three nonimprinted adsorbents (NIPs) were submitted to batch adsorption experiments. After ordering the adsorption models according to the “minimum sum of normalized errors (SNE)” criteria, it was concluded that the adsorption in sclareol imprinted AN:AA copolymers is characterized by low surface coverage, takes place on heterogeneous binding sites and is reversible, while for NIPs the results suggest a difficult adsorption and/or easiness of template extraction, and that NIPs have homogeneous, but nonimprinted micropores. For the kinetic experiments, the minimum SNE for MIPs points to the first order kinetic model, fact that suggests a physical adsorption of template molecules on the imprinted sites. POLYM. ENG. SCI., 55:1152–1162, 2015. © 2014 Society of Plastics Engineers     

Direct synthesis of surface molecularly imprinted polymers based on vinyl–SiO2 nanospheres for recognition of bisphenol A

Molecularly imprinted polymers (MIP) with high performance in selectively recognizing bisphenol A (BPA) were prepared by using a novel and facile surface molecular‐imprinting technique. Vinyl‐functionalized, monodispersed silica spheres were synthesized by a one‐step emulsion reaction in aqueous solution. Then, BPA surface molecularly imprinted polymers (SMIP) were prepared by polymerization with 4‐vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. Maximal sorption capacity (Q_max) of the resulting SMIP was up to 600 μmol g^?1, while that of nonimprinted polymers was only 314.68 μmol g^?1. Kinetic binding study showed that sorption capacity reached 70% of Q_max in 20 min and sorption equilibrium at 80 min. SMIP had excellent accessibility and affinity toward BPA, for the selectivity coefficients of SMIP for BPA in respect to phenol, p‐tert‐butylphenol, and o‐phenylphenol were 3.39, 3.35, and 3.02, respectively. The reusage process verified the SMIP owning admirably stable adsorption capacity toward BPA for eight times. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation of molecularly imprinted polymer films on monodisperse macromolecular beads

A new and facile technique for preparing homogeneous and highly selective molecularly imprinted polymers (MIPs) films on porous monodisperse poly‐(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) beads (P_GMA‐EDMA beads) has been described: before polymerization, initiator was immobilized on the P_GMA‐EDMA beads' surface by chemical reactivity; then functional monomers and crosslinkers were initiated by the surface‐bound initiator and copolymerized to form MIPs films on the P_GMA‐EDMA beads' surface in the presence of template molecules. The resulting beads were analyzed by FTIR spectroscopy and X‐ray photoelectron spectra. The effects of the initiator amount and copolymerization time on the content of MIPs, and MIPs contents on morphologies and pore properties of the resulting beads were investigated. The results show that the content of MIPs can be adjusted by changing initiator amount or by controlling copolymerization time. The binding experiments indicate that, at lower grafting level, with the increase of MIPs content, the adsorption and recognition capabilities of the resulting beads enhance. When MIPs content increase to 16.75%, the highest adsorption and recognition capabilities are obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and adsorption selectivity of deltamethrin molecularly imprinted polymers by two-step seed swelling method

Deltamethrin (DM) is one of the most efficient pyrethroid insecticides, which is widely applied to the control of insect pests in tea. In this work, efficient molecularly imprinted polymers (MIPs) were synthesized using DM as the template and acrylamide as the functional monomer, in conjunction with two-step seed swelling polymerization. Scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area analysis confirmed the staggered pore structure and the presence of binding site in DM MIPs. The adsorption properties of the DM MIPs were also investigated based on assessing equilibrium adsorption as well as kinetic modeling and solid-phase extraction. Isothermal equilibrium adsorption experiments show that the adsorption behavior is consistent with the Freundlich and Halsey models, indicating heterogeneous multilayer specific adsorption. Fitting of the kinetic data demonstrates that chemical adsorption could be the rate-limiting step in DM extraction, which is consistent with a pseudo-second-order kinetic model. Using the imprinted polymers as solid-phase extraction filler, the DM recoveries from various teas were greater than 80% and exceeded those of the structural analogs cypermethrin, lambda-cyhalothrin, and bifenthrin. These results confirm that the MIPs exhibit specific adsorption of this analyte. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47415.     

Magnetic molecularly imprinted polymer nanoparticles coupled with high performance liquid chromatography for solid‐phase extraction of carvedilol in serum samples

Herein, we report a magnetic molecularly imprinted polymers (m‐MIPs) using Fe₃O₄ as a magnetic component, carvedilol as a template molecule for the solid‐phase extraction (MISPE) as the sample clean‐up technique combined with high‐performance liquid chromatography (HPLC) and for the controlled release of carvedilol at different pH values of 1.0 (simulated gastric fluid), 6.8 (simulated intestinal fluid), and 7.4 (simulated biological fluid). The adsorption kinetics was modeled with the pseudo‐first‐order and pseudo‐second‐order kinetics, and the adsorption isotherms were fitted with Langmuir and Freundlich models. The performance of the m‐MIPs for the controlled release of carvedilol was assessed and results indicated that the magnetic MIPs also have potential applications in controlled drug release. Furthermore, the m‐MIPs were applied to the extraction of carvedilol from human blood plasma samples. Carvedilol can be quantified by this method in the 2–350 μg L^?1 concentration range. The limit of detection and limit of quantification in plasma samples are 0.13 and 0.45 μg L^?1. The results from HPLC showed good precision (3.5% for 50.0 μg L^?1) and recoveries (between 85 and 93) using m‐MIP from human plasma samples. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41209.     

Grafting of molecularly imprinted polymers from the surface of Fe3O4 nanoparticles containing double bond via suspension polymerization in aqueous environment: A selective sorbent for theophylline

Molecularly imprinted polymers (MIPs) were grafted from the surface of Fe₃O₄ nanoparticles containing double bond via suspension polymerization in aqueous environment, and the leakage of Fe₃O₄ nanoparticles from MIPs was overcome in this study. The effect of different cross‐linker on adsorption capacity of the resultant magnetic MIPs was investigated using pure trimethylolpropane trimethacrylate (TRIM) or the mixture of TRIM and divinylbenzene (DVB) as cross‐linker. Both magnetic MIPs exhibited higher adsorption capacity for the template theophylline than the corresponding non‐imprinted polymer, and Freundlich model fitted reasonably well for theophylline adsorption on both magnetic MIPs. In addition, both magnetic MIPs exhibited good recognition properties for the template theophylline versus caffeine, and the selectivity of magnetic MIPs using pure TRIM as cross‐linker (mag‐MIP‐TRIM) was much higher than those using the mixture of TRIM and DVB as cross‐linker (mag‐MIP‐TRIM and DVB). The adsorption dynamics of theophylline on both magnetic MIPs fitted well with the first‐order kinetic model, but the adsorption equilibrium on mag‐MIP‐TRIM and DVB reached faster than that on mag‐MIP‐TRIM. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and optimization of molecularly imprinted polymers for quercetin

Molecularly imprinted polymers (MIPs) were synthesized through solution polymerization using quercetin as the template molecule, N‐vinylpyrrolidone and acrylic acid as functional monomers, N,N′‐methylenebiacrylamide as crosslinker and the redox system L ‐ascorbic acid and hydrogen peroxide as initiator in the porogen of ethanol and water. During the optimization process an interference compound, genistein (5,7,4′‐trihydroxy isoflavone), which possesses the same skeleton and functional groups as quercetin, was adopted to optimize the preparation conditions, and the separation degree of the MIP to quercetin and genistein was chosen to optimize each factor. The synthesized MIP under optimal conditions showed a specific recognition of quercetin from a mixture of quercetin and genistein. Thereafter, the structure of the MIP was comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and Brunauer–Emmett–Teller analysis using non‐imprinted molecular polymers as control. In addition, the kinetics of the adsorption process were also studied, and Scatchard analysis revealed that heterogeneous binding sites were formed in the polymers. Copyright © 2012 Society of Chemical Industry