3,3′‐Diindolylmethane imprinted polymers: synthesis,characterization and analytical procedure for template isolation from biological matrix

A novel sorbent for the separation of 3,3′‐diindolylmethane (DIM) has been developed. DIM was used as a template molecule to prepare twelve imprinted polymers from seven different functional monomers in six various porogens in the presence of ethylene glycol dimethacrylate as a crosslinker. The binding capacity showed that the highest binding specificity was achieved when allylamine as the monomer and carbon tetrachloride as the porogen were used to form bulk polymers. Binding capacities were 130.4 ± 2.8 µg g^?1 for imprinted MIP7_a polymer versus 49.03 ± 0.44 µg g^?1 for non‐imprinted NIP7_a polymer. An imprinting factor of 3.12 reflected the high specificity of MIP7_a. A solid‐phase extraction protocol was fully optimized. Two methanol–water systems were selected as the most effective for loading and washing steps, while acetonitrile was chosen as the most efficient eluent suitable for recovery of 91.7 ± 3.8% of DIM. Optimal concentration of DIM and volume of loaded sample were also examined. A loaded volume of 2.5 mL was the most appropriate for 0.625 and 1.25 mg L^?1. The use of MIP7_a for the separations of DIM from spiked bovine serum albumin was evaluated, showing a total recovery of 87.7 ± 3.5%. The commercial sorbent C18 was not suitable for such an application. © 2013 Society of Chemical Industry     

焦性没食子酸分子印迹聚合物的制备与吸附特征研究

以焦性没食子酸为模板分子,丙烯酸为功能单体,甲醇为溶剂,研究了模板分子与功能单体的结合比例,表明焦性没食子酸和丙烯酸之间通过氢键形成1∶1型配合物。在模板分子与功能单体、交联剂物质的量的比为1∶4∶20的条件下,采用沉淀聚合法制备了焦性没食子酸分子印迹聚合物微球。静态吸附实验表明,可制备出吸附量大且特异性识别能力较高的分子印迹聚合物,对焦性没食子酸有较高的亲和性和选择性。采用恒温振荡平衡吸附法以及Scatchard分析研究了聚合物的吸附特征,结果表明焦性没食子酸分子印迹聚合物在水环境下存在2种吸附位点,最大表观吸附量分别为7.5516μg/mg和11.9225μg/mg,平衡离解常数分别为9.2720×10-3mmol/L和0.1892 mmol/L。     

Synthesis of molecularly imprinted microspheres for recognition of trans‐aconitic acid

In the presence of a template molecule, trans‐aconitic acid and, using acetonitrile as solvent and dispersing medium, monodispersed microspheres with a diameter of 600–700 nm bearing molecularly imprinted binding sites were prepared by precipitation polymerization. It was found that the concentrations of template, monomer, and crosslinking agent as well as the chemical structure of the template greatly affect the polymer configuration. Microspheres are produced only when the concentration of the template molecule and the functional monomer are finely tuned. Comparison with the performance of a conventional imprinted polymer monolith showed that the imprinted microsphere had obvious advantages in specific binding to template molecule. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 542–547, 2004     

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     

Zn2+配位双模板印迹聚合物的制备表征及同时萃取升麻中的阿魏酸和咖啡酸

以Zn²⁺-阿魏酸-咖啡酸配合物为模板制备了双分子印迹聚合物,优化了制备条件,用傅里叶红外光谱和扫描电镜对分子印迹聚合物进行结构表征,测试了分子印迹聚合物的吸附特性,探讨了分子印迹聚合物固相萃取应用效能并对萃取条件进行了优化.结果表明,当预反应混合液中金属离子、模板总量(阿魏酸-咖啡酸摩尔比为2:3)、功能单体及交联剂用量比为1:1:3:30(摩尔比)时,所得印迹聚合物对两种模板(阿魏酸和咖啡酸)均具有最好的吸附性能,吸附量分别达51.12mg/g和70.26mg/g.吸附动力学测试表明吸附3h,分子印迹聚合物可达到吸附平衡.用分子印迹聚合物进行固相萃取时,优化的淋洗过程为1.00mL H₂O、1.00mL甲醇-H₂O (3/7,体积比)及1.00mL甲醇-H₂O-ACN (4/4/2,体积比),洗脱溶剂为2.00mL甲醇.在优化条件下,分子印迹聚合物可同时选择富集升麻初提液中的阿魏酸和咖啡酸,二者回收率分别为92.67%和95.42%,而且产品中杂质少于用硅胶萃取所得产品.     

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     

Synthesis of highly selective spherical caffeine imprinted polymers via ultrasound‐assisted precipitation polymerization

A facile and efficient method for synthesis of molecularly imprinted polymers via ultrasound‐assisted precipitation polymerization was developed. Caffeine was applied as a model template in the imprinting using methacrylic acid and ethylene glycol dimethacrylate as a functional monomer and a crosslinker, respectively. Polymerization under sonochemical conditions proceeded rapidly (within 3 h at 60°C) to afford polymer microspheres with narrow size distributions in excellent yields while maintaining the binding specificity toward the template. It was found that the imprinted polymer prepared at low initial temperature (40°C) exhibited the best caffeine binding performance in terms of specificity and selectivity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation,characterization, and adsorption performance of p‐hydroxybenzoic acid imprinted polymer and selective catalysis of toluene to para‐chlorotoluene

A p‐hydroxybenzoic acid surface molecularly imprinted polymer (p‐HB– S MIP) with si lica microspheres as a supporting matrix was prepared by the adoption of the surface molecular imprinting technique with acrylamide ( AM) as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and azoisobutyronitrile as an initiator. The p‐HB–SMIP was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetry. Interactions between the functional monomer and template were observed with UV–visible spectroscopy of the solutions of these components as well. The results indicate that a 1:2 molecular complex was formed between p‐hydroxybenzoic acid (p‐HB) and AM. A kinetic binding study showed that p‐HB–SMIP reached saturation adsorption after about 1 h, and the pseudo‐second‐order model fitted the adsorption kinetics data. Static adsorption experiments revealed that the Freundlich equation fitted the adsorption isotherm data. The thermodynamics parameters (with positive values of enthalpy and entropy and negative values of Gibbs free energy) indicated that the binding system for p‐HB–SMIP was endothermic and entropy was gained and was spontaneous. Selective experiments showed that p‐HB–SMIP had a high affinity and excellent recognition selectivity for the template p‐HB. p‐HB–SMIP was further investigated by the catalysis of toluene to para‐chlorotoluene. The catalytic reaction results showed that the conversion of toluene was 85.5% and the molar ratio of para‐chlorotoluene to o‐chorotoluene was 1.38; this was higher than that of traditional catalysts. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40118.     

格列美脲分子印迹聚合物应用于固相萃取的研究

以降血糖药物格列美脲为模板分子,ɑ-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用本体聚合法制备了格列美脲分子印迹聚合物(MIP),用于血浆样品前处理,建立了对加标兔血浆中格列美脲含量的固相萃取检测方法,通过高效液相色谱法测定,分子印迹固相萃取柱的回收率可达80%以上,有效地减少了基体中蛋白质等杂质对目标物检测的干扰,适用于生物样品中模板分子的富集和纯化。     

Imprinted β‐cyclodextrin polymers using naringin as template

The objective of this study was to identify a kind of molecular imprinting polymer (MIP) which was suitable for recognizing naringin (NG) in aqueous medium. Based on two crosslinkers (hexamethylene diisocyanate and epichlorohydrin) and two polymerization methods (solution polymerization and emulsion polymerization), four non‐covalent naringin‐β‐cyclodextrine (NG‐β‐CD) imprinted polymers were prepared by using β‐CD as a functional monomer and NG as a template molecule. The binding property and selectivity were evaluated by equilibrium binding experiments. These demonstrated that all the sites in the MIPs show good selective binding ability for NG from naringin dihydrochalcone, a structurally similar molecule. Of the four MIPs, rod‐like 3# MIP which was prepared by emulsion polymerization using hexamethylene diisocyanate as crosslinker exhibited the highest selectivity, its imprinting factor α being 1.53. Scatchard analysis of 3# MIP suggests that there are two classes of binding sites during the MIP's recognition of NG. Additionally, the 3# MIP could be used at least five times without any loss in sorption capacity. Copyright © 2011 Society of Chemical Industry     

A new microemulsion approach for producing molecularly imprinted polymers with selective recognition cavities for gallic acid

Bulk and microemulsion systems were studied in order to obtain molecularly imprinted copolymers selective for gallic acid. Both systems contained acrylic acid as the functional monomer and ethylene glycol dimethacrylate as crosslinker. Microemulsion formation was confirmed by refractive index measurements and by conductivity analyses. Simple uptake tests revealed higher affinities for the microemulsion polymers; a 3.55 imprinting factor and a 0.275 g gallic acid (g polymer)^–1 adsorption capacity were recorded. Competitive uptake tests, from an oak bark extract, were in agreement with the simple uptake results and BET analyses. Microemulsion polymer particles selectively bind 4.58 times more gallic acid molecules relative to other competitor species.     

Uniform‐sized clenbuterol molecularly imprinted polymers prepared with methacrylic acid or acrylamide as an interacting monomer

Clenbuterol molecularly imprinted polymer microbeads were prepared with a two‐step swelling and thermal polymerization technique with either methacrylic acid or acrylamide (AAm) as the monomer and ethylene glycol dimethacrylate as the crosslinker at different monomer/crosslinker ratios. The quality of the microbeads, in terms of shape, size distribution, rigidity, and monomer incorporation, was evaluated as a function of the reaction parameters. A good imprinting effect was obtained with both systems, as assessed by high‐performance liquid chromatography (HPLC) experiments with phosphate‐buffered saline/acetonitrile eluents, with a complete baseline separation of clenbuterol with respect to other β‐adrenergic agents obtained. When AAm was used as the monomer, improved control of the polymerization process was achieved, producing microbeads with lower polydispersity and no lack of separation capacity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2660–2668, 2002     

分子印迹固相萃取法提取花生壳中木犀草素

采用分子印迹技术,以木犀草素为模板分子、丙烯酰胺为功能单体、EGDMA为交联剂,合成了木犀草素印迹聚合物。将该印迹聚合物用于固相萃取,分离提取花生壳中的木犀草素。结果表明,该印迹聚合物对木犀草素具有较高的吸附性能和选择性,用印迹柱萃取得到的木犀草素纯度高出硅胶柱分离近20个百分点,达到96.2%。且MIPs-SPE柱与普通的硅胶柱相比,经过洗脱再生后可以反复使用多次。     

Preparation and characterization of magnetic molecularly imprinted polymers for selective recognition of 3‐methylindole

In this work, magnetic molecularly imprinted polymers (MMIPs) were used as novel adsorbents for selective adsorption of 3‐methylindole from model oil. The MMIPs were synthesized by precipitation polymerization and surface molecularly imprinted technique, using Fe₃O₄ nanoparticles as magnetically susceptible component, methylacrylic acid as dressing agent and functional monomer, ethylene glycol dimethacrylate as crosslinker, and 3‐methylindole as template molecule. The MMIPs were characterized by Fourier‐transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer, and thermogravimetric analyzer, respectively. The adsorption performances of MMIPs were investigated by batch adsorption experiments in terms of kinetics, isotherms, and selective recognition adsorption, respectively. The results indicate that MMIPs have high recognition ability and fast binding kinetics for 3‐methylindole. Meanwhile, the adsorption equilibrium time was about 2 h and the equilibrium adsorption amount was ～38 mg g^?1 at 298 K. The heterogeneous MMIPs were modeled with pseudo‐second‐order and Langmuir isotherm equation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2859–2866, 2013     

Morphologies and binding characteristics of molecularly imprinted polymers prepared by precipitation polymerization

Molecularly imprinted polymers using L ‐2‐chloromandelic acid as templates were prepared by precipitation polymerization. The polymer particles exhibited a regular shape in the nanoscale range; moreover, the size and the uniformity of the particles were influenced by the concentration of monomers, polymerization temperature, types and concentrations of initiators. The experimental binding tests indicated that the nanospherical imprinted polymers possessed higher specific affinity to templates in comparison with traditional imprinted polymers prepared by bulk polymerization. Two classes of specific binding sites in the polymer matrix were investigated by the Scatchard method and ‘Hyperchem’ simulation studies. Copyright © 2003 Society of Chemical Industry     

智能印迹聚合物及其外场强化的识别机制研究进展

智能印迹聚合物在外部环境刺激下对模板分子具有响应性分子识别吸附能力,在吸附分离、药物传递、检测、固相萃取、催化等应用领域有着广阔的前景。本文首先对分子印迹聚合物进行了综述并指出在外场强化过程中常规分子印迹聚合物很难通过改变结合位点来控制结合特性的问题,针对这个问题进而提出具有柔性位点的智能响应型印迹聚合物。随后以具有不同响应功能的智能印迹聚合物为出发点,对磁、热、光、pH、生物大分子等单因子及双重因子响应功能印迹聚合物在外场强化过程中的响应与识别机制分别进行分析与总结,并综述了近些年来这些智能印迹聚合物在不同应用领域中相关研究工作进展。最后,基于不同响应功能的智能印迹聚合物的现状问题,对智能印迹聚合物在材料制备与理论两方面分别进行了展望。     

Extraction and determination of malachite green from aquatic products based on molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) were synthesized using malachite green (MG) as template, and methacrylic acid/sodium methacrylate as composite monomers. The equilibrium dissociation constant and apparent maximum adsorption capacity of the MIPs reach 12.2 mg·L^?1 and 3.2 mg·g^?1, respectively. The MIPs demonstrate excellent recognition ability due to high-affinity sites constructed by the electrostatic interaction and hydrogen bonds between template and composite monomers. The MIPs were successfully employed for the detection of MG residue in aquatic products coupled with high-performance liquid chromatography (HPLC) with a detection limit of 0.57 μg·kg^?1.     

Colorimetric and fluorometric molecularly imprinted polymer sensors and binding assays

This mini review examines the utility of molecularly imprinted polymers (MIPs) in colorimetric and fluorometric sensors and binding assays. The review focuses on the challenges in developing MIP‐based spectroscopic sensors. Specifically, strategies to address the low selectivities, lack of sensing mechanism and poor optical material properties of MIPs are examined and critically evaluated using examples from the literature. Copyright © 2007 Society of Chemical Industry     

Preparation of (S)‐ibuprofen‐imprinted polymer and its molecular recognition study

Two molecularly imprinted polymers (MIPs) were prepared using (S)‐ibuprofen as the template molecule as well as methacrylic acid (MAA) or 4‐vinylpyridine and ethylene glycol dimethacrylate (EGDMA) as the functional monomer and crosslinker, respectively. Free radical polymerization was carried out at 4°C under ultraviolet (UV) radiation. The MIPs thus obtained were ground into 25–44 μm, which were slurry packed into analytical columns. The template molecules were removed by acetic acid/methanol solution (1:9, v/v). high‐performance liquid chromatography (HPLC), with UV detection, was used to evaluate the binding performance of the MIP for the template. The selectivity of (S)‐ibuprofen and naproxen on the host–guest system were assessed using acetonitrile‐based mobile phases. The limits of detection of ibuprofen and naproxen were found to be 0.1844 mmol/L and 0.3264 mmol/L, while the limits of quantitation were 0.6262 mmol/L and 1.0909 mmol/L, respectively. The stationary phase was applied successfully to the commercial tablet analysis. Ibuprofen and naproxen were extracted from tablets with acetonitrile; analysis results showed a good relative standard deviation (RSD) of 0.81–1.24% and accuracy from ?4.01 to +2.98% for ibuprofen as well as an RSD of 0.59–0.86% and accuracy from ?4.01 to ?2.01% for naproxen. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2972–2979, 2006