表面定向磁性印迹聚合物的制备及对槲皮素的选择性识别

利用硼酸功能化的磁性碳纳米管作为反应基质, 采用一种简便、 绿色的硼酸亲和表面定向印迹法制备了槲皮素磁性分子印迹聚合物, 并将其应用于银杏叶提取物中槲皮素的特异性识别. 透射电子显微镜、 X射线光电子能谱仪、 X射线衍射及振动样品磁强计测试结果表明, 制备的分子印迹聚合物具有良好的形貌和晶型结构. 吸附实验结果表明, 该分子印迹聚合物对模板分子槲皮素具有较好的吸附容量(4.57 μg/mg)、 良好的印迹效果(IF=8.44)和再生能力. 对实际中药样品银杏叶提取物的吸附实验结果表明, 所建立的方法能达到预期的槲皮素检测效果, 可作为中药有效成分槲皮素的特异性识别工具.     

基于活性自由基聚合的槲皮素分子印迹聚合物的合成及在维药祖卡木颗粒活性成分分析中的应用

以二苄基三硫代碳酸酯(DBTTC)为可逆加成-断裂链转移剂(RAFT试剂),槲皮素(Quercetin)为印迹化合物,分别以甲基丙烯酸(MAA)、丙烯酰胺(AM)、丙烯酸(AA)、4-乙烯基吡啶(4-VP)和2-乙烯基吡啶(2-VP)作为功能单体,利用可逆加成-断裂链转移自由基聚合法制备了槲皮素分子印迹聚合物.实验考察了不同的制备条件,利用氮吸附测试及扫描电子显微镜对聚合物的结构进行了测定,采用色谱法对印迹聚合物的识别能力及分离效率进行了评价.研究了聚合条件-聚合物结构-分离效率的关系,探讨了利用活性自由基合成分子印迹聚合物的方法及特点;并将合成的分子印迹聚合物用作固定相,对维药祖卡木颗粒中的槲皮素进行了分离富集.研究结果表明,通过活性自由基聚合法合成的分子印迹聚合物具有更好的形态结构,对目标分子具有很好的吸附效率.     

琥珀酸氯霉素分子印迹聚合膜的制备及其吸附特性研究

为制备对琥珀酸氯霉素分子具有特异性吸附的分子印迹聚合物膜, 利用模板分子琥珀酸氯霉素(HS-CAP)、功能单体甲基丙烯酸(MA)、交联剂乙二醇二甲基丙烯酸酯(EGDMA)、引发剂偶氮二异丁腈(AIBN)、溶剂四氢呋喃, 采用紫外光引发聚合的方法制备出含有HS-CAP分子印迹位点的印迹聚合微粒, 并使用相转化的方法, 制备含有这种HS-CAP分子印迹微粒的醋酸纤维素膜. 然后通过吸附实验检测该印迹膜的吸附特性, 与非印迹膜相比, 印迹膜对模板分子具有良好的特异性识别作用, 与印迹膜相互作用的模板分子溶液, 在作用前后浓度发生了显著的变化; 印迹膜对模板分子的识别作用主要集中于与模板分子相互作用的最初2 h之内, 并随作用时间的延长而降低; 当模板分子浓度介于0.2～0.0125 mg/mL这一范围内时, 模板分子溶液浓度越高, 印迹膜的吸附特性越明显. 本实验所制备的分子印迹聚合膜对模板分子具有特异性识别能力, 可以在下一步研制以分子印迹聚合膜为基础的检测氯霉素残留的传感设备中得到应用.     

尼泊金乙酯分子印迹固相萃取小柱的研制及应用

研制了一种对尼泊金乙酯具有特异性识别性能的分子印迹固相萃取小柱。用本体聚合法制备尼泊金乙酯分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其固相萃取性能,并结合UV法对滴眼液中的尼泊金乙酯进行测定。结果显示,尼泊金乙酯模板聚合物的吸附能力强于空白聚合物;印迹固相萃取柱对尼泊金乙酯标准溶液(0.04mmol/L)一...     

合成引发方式对槲皮素-钴(Ⅱ)配位印迹聚合物结构与性能的影响

以槲皮素-钴(Ⅱ)的配合物为模板分子,在强极性甲醇溶剂中分别采用低温光引发和高温热引发聚合制备槲皮素-钴(Ⅱ)配位印迹聚合物.紫外-可见光谱分析确定了槲皮素与钴(Ⅱ)形成配合物的最佳配位比.根据印迹聚合物的平衡结合量优化功能单体丙烯酰胺用量.利用红外光谱、透射电镜和平衡结合实验,考察不同引发方式对聚合物的结构、微观形貌及结合性能的影响.进一步通过特异吸附容量和印迹指数确定,低温光引发聚合更适于配位分子印迹聚合物的制备.同时研究了不同阳、阴离子对印迹聚合物选择识别性的影响.结果表明光引发的金属配位分子印迹聚合物具有良好的吸附选择性,印迹指数可达3.919.     

槲皮素表面分子印迹聚合物的制备及其应用研究

以接枝双键的凹凸棒土(TM)为载体,槲皮素为模板分子,采用表面印迹技术制备对槲皮素具有特异吸附性能的分子印迹聚合物(MIP)。利用光谱法选择实验条件及对化合物表征。采用静态法研究聚合物对槲皮素的结合性能与识别性能。结果表明,该分子印迹材料对槲皮素具有特异的识别特性和优良的亲和性,提高了传统聚合物的结合率。以该印迹聚合物为固相萃取材料,结合高效液相色谱法,对白菜中的槲皮素进行分离富集,方法回收率为84.0%~90.6%,相对标准偏差低于5.6%。     

电子束辐射聚合制备槲皮素-镍(Ⅱ)金属配位分子印迹聚合物及其识别性能研究

以电子束为辐照射线源,采用辐射聚合法成功制备了槲皮素-Ni(Ⅱ)金属配位分子印迹聚合物.通过紫外光谱研究了槲皮素与Ni(Ⅱ)之间的配位结构、配位作用方式及配位比,并按照1∶2的比例形成稳定配合物,同时也验证了槲皮素、Ni(Ⅱ)及功能单体甲基丙烯酸三者发生了金属配位印迹作用.利用红外光谱对产物的结构进行了表征.透射电镜、扫描电镜、吸附动力学实验分别考察辐射剂量对聚合物的微观形貌、吸附动力学性能的影响,结果表明辐射剂量对印迹聚合物的吸附性能有显著影响.同时选择性吸附实验结果显示该印迹聚合物对槲皮素-Ni(Ⅱ)配合物表现出明显的吸附选择性和特异性,最大结合量可达82.22μmol/g.对黄芩素和柚皮素的吸附选择性较差,分离因子分别为3.915和5.443.     

槲皮素金属配位分子印迹聚合物的识别性能

以槲皮素与Zn(Ⅱ)的配合物为模板,在甲醇溶液中制备金属配位分子印迹聚合物.通过紫外光谱研究了槲皮素与Zn(Ⅱ)的配位方式及配位比,验证了槲皮素、Zn(Ⅱ)和4-乙烯基吡啶之间的三元配位作用.利用红外光谱对产物的结构进行了表征.用平衡结合实验考察了功能单体及交联剂用量对聚合物吸附性能的影响,优化了聚合物的反应配比.同时对系列印迹聚合物的识别体系进行了考察.结果表明,槲皮素-Zn(Ⅱ)模板印迹聚合物对槲皮素-Zn(Ⅱ)的配合物表现出明显的吸附选择性和特异性,对槲皮素结构类似物芦丁和柚皮素的吸附选择性较差,分离因子分别为3.21和1.91.     

非那西汀印迹聚合物固相萃取性能研究

研究非那西汀分子印迹聚合物的固相萃取性能。用本体聚合法制备非那西汀分子印迹聚合物,通过静态平衡吸附试验及固相萃取试验,研究其固相萃取性能。非那西汀模板聚合物的吸附能力明显强于空白聚合物。模板聚合物对浓度为0.03mmol/L的非那西汀标准溶液一次性萃取率为74.2%。非那西汀印迹聚合物对非那西汀具有特异性识别性能,可作为固相萃取固定相的应用研究。     

正丁醇分子印迹聚合物的制备及其吸附性能

以正丁醇为模板分子,采用本体聚合法制备了正丁醇分子印迹聚合物。利用扫描电镜和红外光谱对该聚合物进行表征,并利用动态吸附、静态吸附和选择性吸附实验评价其吸附性能。正丁醇分子印迹聚合物能够特异性识别正丁醇,通过计算得到正丁醇MIPs的分离因子α为2.057,印迹因子IF为2.123。此聚合物制备简单、可重复利用并且表现出良好的选择性,可作为固相萃取填料应用于食品中正丁醇的分离、富集和检测。     

Synthesis and characterization of a novel quercetin magnetic molecularly imprinted polymer via reversible addition fragmentation chain transfer strategy

Molecularly imprinted polymer (MIP) will be modified on the surface of the core-shell structure silica magnetic nanoparticles, during which quercetin is used as a template molecule, acrylamide as a functional monomer, azo-bisisobutyronitrile as an initiator and ethylene glycol dimethacrylate as a cross-linker, to synthesize highly efficient and selective quercetin magnetic molecularly imprinted nanoparticles via Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization. FT-IR and X-ray diffraction (XRD) patterns are used to monitor the reaction and show the characteristic groups of each reaction step. Compared with the conventional bulk polymerization (2.7029 mg/g), the adsorption test showed that the MMIP by RAFT activity controlled polymerization had better absorption capacity for quercetin which the saturated adsorption amount was 4.8471 mg/g. Kinetic studies indicate that pseudo first order model is suitable to describe the adsorption mechanism. Thermodynamics experiment revealed that Langmuir model was more applied for explains the adsorption of quercetin onto magnetic molecularly imprinted polymer.     

多壁碳纳米管表面熊果酸印迹聚合物的制备及固相萃取

以聚乙烯醇修饰的多壁碳纳米管(MWCNTs)为基材,熊果酸(UA)为模板分子,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,采用表面印迹技术在碳纳米管表面合成对熊果酸具有良好选择性的分子印迹聚合物( MWCNTs-MIPs).讨论了不同摩尔比例的功能单体与模板分子合成印迹聚合物的效果,得出...     

基于纳米材料修饰的高灵敏性L-苯丙氨酸印迹溶胶-凝胶传感器的研究

将氧化锌纳米膜(ZnO-NFs)、多壁碳纳米管(MWNTs)、纳米铜颗粒(Cu-NPs)和印迹溶胶-凝胶聚合物(MIP)依次修饰到碳电极(CE)表面,制备了一种对L-苯丙氨酸具有特异识别能力的印迹电化学传感器.采用电子扫描显微镜(SEM)对各修饰电极进行形貌表征;采用循环伏安法(CV)、示差脉冲伏安法(DPV)、安培时...     

Polymer coating of carboxylic acid functionalized multiwalled carbon nanotubes via reversible addition‐fragmentation chain transfer mediated emulsion polymerization

In this work, successful polymer coating of COOH‐functionalized multiwalled carbon nanotubes (MWCNTs) via reversible addition fragmentation chain transfer (RAFT) mediated emulsion polymerization is reported. The method used amphiphilic macro‐RAFT copolymers as stabilizers for MWCNT dispersions, followed by their subsequent coating with poly(methyl methacrylate‐co‐butyl acrylate). Poly(allylamine hydrochloride) was initially used to change the charge on the surface of the MWCNTs to facilitate adsorption of negatively charged macro‐RAFT copolymer onto their surface via electrostatic interactions. After polymerization, the resultant latex was found to contain uniform polymer‐coated MWCNTs where polymer layer thickness could be controlled by the amount of monomer fed into the reaction. The polymer‐coated MWCNTs were demonstrated to be dispersible in both polar and nonpolar solvents. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

表面分子印迹高分子膜修饰硅胶用于血清中茶碱的固相萃取

采用表面引发可逆加成-断裂链转移自由基聚合反应,在硅胶表面修饰了分子印迹高分子膜(MIP-silica)。以元素分析和氮吸附分析对修饰的分子印迹高分子膜进行了表征。与传统采用本体聚合合成的分子印迹高分子相比,MIP-silica具有更好的传质能力。本文合成的茶碱印迹MIP-silica可以作为选择性固相萃取材料从血清中富集、检测微量的茶碱,该法合成的MIP-silica还可用于高效液相色谱和毛细管电色谱等领域。     

Controllable Preparation and Application of Quercetin Molecularly Imprinted Polymer

The quercetin molecularly imprinted polymer microspheres were prepared by reversible addition-fragmentation chain transfer free radical polymerization combined with precipitation method (RAFTPP) with the dibenzyl trithiocarbonate (DBTTC) as RAFT reagent and quercetin as template molecule. The effects of solvents and cross-linking agent on the morphology and size of polymers were investigated, and the polymers were preliminarily screened by scanning electron microscope. The adsorption experiment and adsorption model analysis were carried out on the molecularly imprinted polymers (R-MIP) prepared under optimal condition and on the molecularly imprinted polymers prepared with a traditional precipitation polymerization (T-MIP). Consequently it was determined that, QR-MIP max was 37.71 mg g^?1 and QT-MIP max was 29.61 mg g^?1. The results showed that the R-MIP had a good adsorptive property and was obviously superior to T-MIP. R-MIP was used as solid-phase extraction filler in combination with the HPLC method to conduct enrichment, separation and measurement of the quercetin in honeysuckle and clove leaves, which effectively removed the matrix interference and the recovery rate of this method was 93.8–102.9%.

     

Grafting of MIPs from PVDF Membranes via Reversible Addition-fragmentation Chain Transfer Polymerization for Selective Removal of p-Hydroxybenzoic Acid

Effective molecularly imprinted membranes(MIMs) were developed as an efficient adsorbent for the selective removal of p-hydroxybenzoic acid(p-HB) from acetylsalicylic acid(ASA, aspirin). The MIMs were grafted successfully from poly(vinylidene fluoride) microfiltration membranes via reversible addition-fragmentation chain transfer(RAFT) polymerization. The graft copolymerization of acrylic acid(AA) in the presence of template p-hydroxybenzoic acid led to molecularly imprinted polymer(MIP) film coated membranes. The obtained MIMs were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectrophotometer(FTIR) and Raman spectra, and batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics and selective recognition properties of different MIMs. The kinetic properties of the MIMs could be well described by the pseudo-second-order rate equation. Selective permeation experiments were performed to evaluate the permeation selectivity of the p-HB imprinted membranes. The observed performances of the MIMs are applicable to the further purification of aspirin.     

基于多壁碳纳米管增敏材料的辣根过氧化物酶分子印迹电化学传感器的制备及对H2O2的检测

以辣根过氧化物酶(HRP)为蛋白质模板分子, 邻苯二胺(o-PD)为聚合单体, 首先将预先羧基化的多壁碳纳米管(MWCNTs)通过阶跃电位法电沉积在玻碳电极上作为增敏材料, 然后在该电极上电聚合含HRP的邻苯二胺电沉积液形成一层聚合膜, 去除模板化合物后, 制得对HRP具有特异性识别能力的分子印迹聚合物(MIPs)膜; 利用聚邻苯二胺(POPD)的自探针效应构建了分子印迹电化学传感器. 该传感器的响应电流与HRP浓度在1.0×10 ^-10~1.0×10 ^-5 mg/mL范围内有良好的线性关系, 相关系数为0.991, 检出限为1.5×10 ^-11 mg/mL(S/N=3); 该传感器的响应电流与H₂O₂浓度在4.0×10 ^-7~1.4×10 ^-5 mol/L范围内有良好的线性响应, 相关系数为0.992, 检出限为2.6×10 ^-7 mol/L(S/N=3), 将该传感器用于实际样品H₂O₂的检测, 回收率在91.2%~97.1%之间. 建立了基于MIPs膜的HRP和H₂O₂双分析物传感器的制备方法, 该方法可应用于酶及其酶促底物双分析物传感器.     

Preparation of a Pyrazosulfuron-Ethyl Imprinted Polymer with Hydrophilic External Layers by Reversible Addition-Fragmentation Chain Transfer Precipitation and Grafting Polymerization

A new imprinted polymer with both functions of molecular recognition and macromolecule exclusion was synthesized for selective extraction of pyrazosulfuron-ethyl and removal of humic acids in environmental analysis. In the preparation, spherical pyrazosulfuron-ethyl imprinted polymers were synthesized by reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization. The hydrophilic polymer layers were then grafted on the surface of the imprinted polymer microspheres using post-RAFT polymerization. The conditions that influence the selectivity, size, and uniformity of the imprinted microspheres were studied systematically. The computer simulation was employed to study the template-monomer interaction. The solubility parameters of poly(MAA-co-EDMA) and porogen were calculated to investigate the relationship between the particle size and the solubility parameter. The results indicated that the pyrazosulfuron-ethyl imprinted polymers have special affinity for the template and several structurally related sulfonylurea herbicides. The molecularly imprinted polymer (MIP) with external hydrophilic chains not only had function of template retention, but also better function of protein/humic acid exclusion. This research demonstrates that multifunctional imprinted material with a narrow size distribution can be prepared by the RAFT polymerization.