Molecularly Imprinted Polymer Film Grafted from Porous Silica for Selective Recognition of Testosterone

Abstract

A type of testosterone‐imprinted polymer film grafted from porous silica was prepared by covalently binding azo‐initiators and then photo‐grafting. Elemental analysis and infrared (IR) spectroscopy attested the polymer formation. The material could be polymerized within 10–60 min with reproducible grafting kinetics, controllable film thickness, and obviously specific recognition ability to testosterone with the imprinting factor of 1.52. Due to its uniform size, spherical shape, controllable film thickness, and accessible sites near or at the surface, this polymer could serve as a sensing element, solid‐phase extraction material, or chromatographic stationary phase to selectively recognize or separate testosterone.     

Molecularly Imprinted Polymer with Calix[4]arene Derivative for the Recognition of Acetanilide

Two molecularly imprinted polymers binding to analgesic acetanilide were prepared using either dual functional monomers of calix[4]arene derivative and acrylamide or single monomer acrylamide, respectively. The polymers were ground, sieved and investigated by equilibrium binding experiment to evaluate their recognition properties for the template and other substrates. Scatchard analysis showed that homogeneous recognition sites were formed in the imprinted polymer matrix. Our results demonstrated that the polymer using two functional monomers exhibited better selectivity for the template. This study may open new frontiers for the development and application of imprinted polymers, such as drug separation and purification.     

Synthesis and Molecular Recognition of Molecularly Imprinted Polymer with Ibuprofen as Template

Ibuprofen and ketoprofen are chemically similar non‐steroidal anti‐inflammatory drugs widely used in the treatment of arthritis. Using a molecular imprinting technique, a simple and rapid method was developed for the simultaneous separation and determination of ibuprofen and ketoprofen. Molecular imprinting introduces artificial binding sites into a synthetic polymer matrix, allowing it to exhibit selective rebinding of template molecules. Imprinted polymers can be regarded as an HPLC stationary phase, important for pharmaceutical analysis. Most molecularly imprinted polymers (MIPs) are synthesized by free radical polymerization of functional monomers, resulting in an excess of crosslinking monomers. In this study, MIPs have been prepared with a ibuprofen template, which can form intramolecular hydrogen bonds. Methacrylic acid (MAA) and ethyleneglycol dimethacrylate (EGDMA) were used as the functional monomer and cross‐linker, respectively. Bulk polymerization was carried out at 4 °C under UV radiation. The resulting MIP was ground into 25?44 μm particles, which were slurry‐packed into analytical columns. Template molecules were removed by methanol‐acetic acid (9:1, v/v). We evaluated the template binding performance of the MIP using HPLC, with ultraviolet (UV) detection at 234 nm. Chromatographic resolution of ibuprofen and ketoprofen on the MIPs were appraised using buffer/acetonitrile (45/55, v/v) as the mobile phase. Results show that the MIPs prepared using ibuprofen as the template had a significant molecular imprinting effect. The method was successfully applied to the separation and analysis of ibuprofen and ketoprofen in pharmaceuticals.     

一种新型分子印迹聚合物基的化学发光阵列传感器

建立了一种分子印迹-化学发光阵列传感器测定甘氨酸的新方法. 该方法以甘氨酸为模板分子, 合成了分子印迹聚合物微球, 将该聚合物微球固定在96孔板上, 用它来识别丹磺酰氯标记的甘氨酸(Dns-Gly). 最后加入化学发光试剂(TCPO-H2O2-咪唑), 测量相对化学发光强度定量检测甘氨酸. 在最佳试验条件下, 相对化学发光强度和甘氨酸的浓度在0.2～60 μmol/L范围内成良好的线性关系, 相关系数为r＝0.9972, 方法的检出限为0.07 μmol/L, 对1 μmol/L甘氨酸溶液进行11次平行测定, 相对标准偏差为3.3% (n＝11). 由于以甘氨酸为模板分子合成出来的分子印迹聚合物空腔比较小, 避免了非特异性吸附, 使它在识别丹磺酰氯标记的甘氨酸时特异性、响应速度和灵敏度都有所增强.     

以分子印迹聚合物为固定相分离和测定氟喹诺酮类药物

以氧氟沙星作为模板分子合成了分子印迹聚合物,并通过高效液相色谱法研究了印迹聚合物的识别特性。实验结果表明,印迹聚合物对模板分子具有很强的亲和力和特定的选择性。作为色谱固定相,氧氟沙星印迹聚合物和目标分子之间的相互作用除了印迹部分的离子和氢键作用外,也存在非印迹部分的疏水作用。同时研究了色谱条件对氟喹诺酮类药物分离的影响。     

Selective Adsorption and Molecular Recognition by a Molecularly Imprinted Polymer: Kinetic Study and Analysis

This article presents an original work aiming at kinetically surveying the substrate‐selective mechanism from a molecularly imprinted polymer. With Bisphenol A (BPA) as the template, the imprinted polymer was prepared. The result indicates that the imprinted polymer presents a much more complicated sorption toward the template than toward its analogue. The rate constant in the case of the template appears to be a function of coverage degree. There are also significant deviations from the idealized Langmuir model. Related information indicates that these logically can be a result from the induced molecular memory within the binding framework, which makes the polymer capable of selectively adsorbing the imprint species.     

烟嘧磺隆分子印迹聚合物表面等离子共振传感器的制备与分析应用

利用分子印迹技术与表面等离子共振光谱联用, 建立了对磺酰脲类除草剂烟嘧磺隆的检测方法. 实验过程中, 探讨了pH值对分子印迹膜吸附目标化合物特性的影响, 并在最佳pH下对其吸附和选择性能进行了评价. 与非印迹聚合物相比, 烟嘧磺隆印迹聚合物对烟嘧磺隆吸附效率比烟嘧磺隆类似物高. 该方法的线性范围为5.0×10^－12～25× 10^－12 mol/L, 烟嘧磺隆和分子印迹聚合物之间的结合常数为1.6×10¹⁰ L/mol, 吉布斯自由能变化值为－58.148 kJ/mol. 研究结果表明该方法具有简单、快速、灵敏度高、重复性好等特点, 适用于自来水和土壤中磺酰脲类除草剂烟嘧磺隆的测定, 基于信噪比为3时, 自来水和土壤的检出限分别为5.62×10^－14和1.01×10^－13 mol/L, 平均回收率分别为85.6%和76.6%, 相对标准偏差分别为1.78%和3.21%.     

Microspheres Sensor Based on Molecularly Imprinted Polymer Synthesized by Precipitation Polymerization

IntroductionSincethepiezoelectricbulkacousticwave (BAW)sen sorswereappliedinliquidphaseinthe 1980s ,manypapershavebeenreported .1,2 However,theapplicationofBAWsen sorsbasedonmasseffectislimitedbecauseoflackofthespecialselectivitytotheanalyte.Variousmethodshavebeenproposedtosolvethisproblem ,especiallytheapplicationofthebiomaterials .3Unfortunately ,theresultwasnotsogoodasexpected,duetotheinstinctdisadvantageofthebiomateri als ,e.g .,poorstability ,shortlifespan ,althoughpossess inghighselec…     

反乌头酸分子印迹聚合物微球的制备及其分子识别功能

以乙腈为分散剂,采用沉淀聚合法合成了反乌头酸分子印迹聚合物微球。研究了合成反应条件对聚合物形貌的影响,发现聚合前主客体氢键络合物和功能单体氢键低聚体是控制微球形成及其粒径大小的关键因素。通过振荡吸附法对聚合物的结合特性进行了评价,发现印迹聚合物微球对模板分子的识别选择性优于块状印迹聚合物和非印迹聚合物。     

Calorimetric Investigation of Chiral Recognition Processes in a Molecularly Imprinted Polymer

The molecular imprinting of polymers is a promising concept for designing highly selective receptor systems which is now fairly well understood from a structural point of view. However, only limited information is available on the thermodynamics of enantioselective recognition in imprints. In order to study this problem, the interactions of a pair of enantiomers (phenyl--L- and phenyl--D-mannopyranoside) with a well-characterized imprinted polymer (D-enantiomer acted as template) have been investigated by means of isothermal batch and titration calorimetry. Batch calorimetric measurements with unstirred samples are affected by strong solvent–polymer interactions, such as swelling, causing large changes of the blank effects over long periods of time. Isothermal titration calorimetric measurements proved to be more efficient for studying imprinted polymers. The enthalpies of rebinding for both enantiomers strongly decrease with increasing degree of occupation of the available cavities. Only at low degrees of occupation (< 50%) was a significantly higher endothermic heat effect for the (D)-enantiomer (template) detected which indicates an enantioselective rebinding. The overall heats of rebinding were found to be endothermic and are composed of several different contributions that are discussed. In summary, the reported calorimetric results are generally in accordance with the proposed mechanism of chiral recognition in this type of molecular imprinted polymers.     

尼卡地平分子聚合物的制备及识别性能研究

采用分子印迹技术合成了以尼卡地平为模板分子,甲基丙烯酸为功能单体的分子印迹聚合物(MIP).运用平衡结合实验研究了聚合物的吸附特性和选择识别能力.通过Scatchard方程分析,结合位点的离解常数Kd=1.03 mmol·L-1,最大表观结合常数Qmax=18.76 μmol·g-1.结果表明,分子印迹聚合物对尼卡地平呈现出较高的吸附性和选择识别性,对尼卡地平药物的分离富集和检测具有实际临床意义.     

磁性分子印迹聚合物萃取/高效液相色谱检测蔬菜中的灭多威

以磁性分子印迹聚合物为吸附剂,建立了蔬菜中灭多威的快速、选择性分析方法。以灭多威为模板分子,甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,Fe3O4为磁性组分制备该聚合物。通过红外光谱、扫描电镜以及综合物性测量仪对合成的聚合物进行表征。Scatchard分析表明磁性分子印迹聚合物对灭多威有两种结合方式,最大表观吸附量(Qmax)和平衡离解常数(Kd)分别为Qmax1=0.053 04 mmol/g,Kd1=0.314 35 mmol/L;Qmax2=0.130 51 mmol/g,Kd2=1.921 22 mmol/L。动力学结果显示该聚合物对灭多威的吸附符合准二级动力学模型。与其它物质相比,制备的聚合物对灭多威具有高选择性识别性能。考察了萃取溶剂、聚合物用量、萃取时间、振荡速度、解析溶剂对灭多威回收率的影响。采用高效液相色谱对灭多威进行检测,检出限为0.012 mg/kg,RSD为2.2%～6.1%,加标回收率为86%～94%。该方法应用于检测甘蓝、小白菜、西红柿、黄瓜和辣椒中的灭多威。结果显示在西红柿样品中检出有灭多威,其含量为1.135 mg/kg。与传统的方法相比,该方法快速、有效,在食品农药残留的分析中具有很好的前景。     

Rationally Designing Molecularly Imprinted Polymer Toward a High Specific Adsorbent by Using Metal as Assembled Pivot

This article presents an original work aimed at rationally designing molecularly imprinted polymer (MIP) toward a high specific adsorbent. Assembling with cobalt as the pivot, the MIP was prepared by coordinating polymerizable monomers around an inducible template. The use of pivot obviously plays a positive role on increasing the specificity of MIP, so as to adsorb more for the template and less for its analogue. Related studies indicate that these may be a result of increasing specific interaction, which makes the MIP capable of recognizing the imprint species. Further information from thermodynamic analysis reveals that the increasing specific interaction, in logic, can be due to a higher fidelity of imprint, which specifically allures the template to bind.     

分子印迹聚合物修饰电化学晶体管检测抗坏血酸分子

以抗坏血酸(AA)为模板分子、邻苯二胺(o-PD)为功能单体,在金电极表面电聚合制备分子印迹聚合物膜(MIP),并以该MIP修饰的电极为栅极制备了具有高选择性、高灵敏度的AA电化学晶体管(OECT)传感器件。应用循环伏安法(CV)、交流阻抗法(EIS)对分子印迹聚合物电极进行一系列的表征与检测。实验结果表明:以pH=5.2,浓度为0.2mol/L HAc-NaAc(体积比2.1∶7.9)的缓冲液为背景溶液,o-PD与AA的物质的量之比为1∶2,以0.5V/s的扫描速率在0~0.8V内扫描20圈,所得分子印迹膜电极性能最佳。应用以该分子印迹修饰电极作为栅极的电化学晶体管检测AA,得到AA浓度的检测限为0.3μmol/L,沟道电流与AA浓度在0.3~3μmol/L(低浓度)与3~100μmol/L(高浓度)这2个范围内成线性关系。     

Molecular Dynamic Study of Mechanism Underlying Nature of Molecular Recognition and the Role of Crosslinker in the Synthesis of Salmeterol-Targeting Molecularly Imprinted Polymer for Analysis of Salmeterol Xinafoate in Biological Fluid

The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24% of SLX in spiked serum and 92.25 ± 1.12% when SLX was spiked with another analogue structure. Compared with the standard solid phase extraction sorbent C-18, which had a recovery of 79.11 ± 2.96%, the MIP showed better performance. The harmony between the simulation and experimental results illustrates that the molecular dynamic simulations had a significant role in the study and development of the MIPs for analysis of SLX in biological fluid.     

应用分子印迹磁性搅拌棒/高效液相色谱检测鱼饲料中的孔雀石绿

采用二步包裹修饰后的高磁性超顺材料钕铁硼磁粉作为磁性供体,以孔雀石绿(MG)为模板,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,利用原位聚合法制备了新型整体式分子印迹吸附萃取搅拌棒(MIP-SBSE),并与高效液相色谱(HPLC)联用测定鱼饲料中的孔雀石绿。考察了吸附和解吸时间、pH值和盐浓度对目标化合物萃取性能的影响。结果表明:在最优条件下,MIP-SBSE可对模板分子进行有效的选择性吸附,线性范围为10~500μg/L;检出限为103~215 ng/L,用该方法对鱼饲料中的孔雀石绿进行分析测定,测得加标回收率为87.3%~94.1%。     

发光性分子印迹聚合物的合成及其对组胺的识别性能研究

以组胺为模板分子,α-甲基丙烯酸为共功能单体,锌原卟啉为荧光功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了一种新的发光性分子印迹聚合物.通过振荡吸附后检测悬浊液荧光和柱吸附后检测流出液中组胺紫外光谱的变化,对印迹和非印迹聚合物与组胺的结合特性进行了对比.两种方法的结果一致,表明印迹聚合物对模板分子的识别选择性优于非印迹聚合物.     

卡维地洛印迹聚合物的合成及其识别性能的研究

以卡维地洛药物分子为模板,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用紫外光引发聚合的分子印迹技术,成功制备出卡维地洛分子印迹聚合物。用热重分析、扫描电镜对聚合物进行了表征,通过Scatchard方程研究了印迹聚合物对模板分子的结合特性。结果表明,在所研究的浓度范围内,印迹聚合物存在一类等价的结合位点,并计算出印迹聚合物与模板分子的平衡离解常数为0.5642 mmol/L,最大表观吸附量为97.44μmol/g,为理论值的63.53%。对不同底物的结合实验表明,该聚合物对卡维地洛具有优良的吸附选择性。     

Synthesis,Application, and Molecular Recognition Mechanism Study of Phenylalanine Molecularly Imprinted Polymer

Abstract

Phenylalanine molecularly imprinted polymer was synthesized in the presence of triflouroacetic acid. HPLC‐MS evaluation showed it had good affinity toward its template among 16 amino acid mixtures. It was used for quantification of phenylalanine in protein hydrolysis solution and in serum without sample pre‐treatment. Further study revealed the molecular recognition mechanism involved size exclusion, hydrophobic interaction, and hydrogen bonding interaction. The molecularly imprinted polymer presented here can be used for actual sample analysis and the well characterized recognition mechanism can benefit the design, synthesis, and application of MIP.     

Voltammetric Determination of Valaciclovir Using a Molecularly Imprinted Polymer Modified Carbon Paste Electrode

A molecularly imprinted polymer (MIP) was rationally synthesized with the aid of computer based studies. The computational studies were used to screen for the most suitable template to functional monomer molar ratio. Two functional monomers were involved in the study (methacrylic acid and 4‐vinylpyridine). Four MIP ratios were synthesized in accordance with the results of the computational studies and their performance was evaluated using equilibrium rebinding assays. The MIP with the best performance was used as an additive in carbon paste electrodes for the voltammetric determination of valaciclovir (VCV). Following the optimization of voltammetric parameters, a linear response was obtained in the range of 1.0x10⁻⁶–7.0x10⁻⁴ M with a limit of detection at 4.45x10⁻⁷ M. The MIP modified carbon paste electrode was successfully applied for the determination of VCV in pure solutions and dosage form.