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.     

锌-槲皮素配位分子印迹聚合物膜渗透特性的研究

采用紫外光引发原位聚合的方法制备了以聚偏氟乙烯管状微孔滤膜为支撑膜的锌离子配位分子印迹聚合物膜. 通过膜渗透实验表明, 在一定浓度锌离子存在下, 印迹膜对模板分子槲皮素表现出良好的渗透选择性. 分别考察了阳离子和阴离子对印迹膜渗透模板分子的影响. 本工作对分子印迹技术应用于实际样品中槲皮素的分离与富集具有重要意义.     

钴离子配位分子印迹聚合物膜渗透特性的研究

采用分子印迹技术紫外光引发原位聚合的方法制备了带支撑膜的钴离子配位分子印迹聚合物膜. 用扫描电镜测定了膜的表面形貌. 通过膜渗透实验表明, 在一定浓度钴离子存在下, 印迹膜对模板分子表现出良好的渗透选择性. 分别考察了阳离子和阴离子对印迹膜渗透模板分子的影响. 本工作有助于分子印迹技术应用于传感器技术和连续分离技术的研究.     

分子印迹膜的制备研究进展

将分子印迹技术与膜分离技术相结合的分子印迹膜,由于其高选择性,近年来受到了国内外研究者的广泛关注.本文初步探讨了分子印迹膜(MIM) 的两种分离机理以及目前主要的制备方法:同步法和复合法.     

赤霉酸分子印迹聚合物及印迹膜的制备与性能研究

以赤霉酸(GA3)为印迹分子,改变功能单体与致孔剂种类合成了四个分子印迹聚合物(MIP1-4)及两个分子印迹膜(MIM1-2).采用紫外光度法分别测定了印迹分子分别与功能单体丙烯酰胺(AM)和甲基丙烯酸(MAA)间的结合常数和化学计量比(n＝2).平衡结合实验研究表明,以AM为单体制备的MIP1对印迹分子GA3具有更高的结合量和良好的印迹效率.膜渗透及膜过滤实验表明,以AM为单体制备的MIM1对GA3分子具有一定的选择性分离性能.     

分子印迹聚合物膜对氨基酸海因手性化合物的选择性结合和透过性质研究

合成了可对氨基酸海因对映异构体选择性分离的分子印迹聚合物膜。利用紫外光谱法比较不同功能单体与模板分子的作用能力。以丙烯酰胺为功能单体,在极性溶剂中制备了5R-5氨-基酸海因的分子印迹聚合物膜,通过Scatchard分析法研究膜中结合位点情况。通过膜透过实验研究印迹膜对外消旋体的分离特性。Scatchard分析显示聚合物膜中形成了两类结合位点,其解离常数分别为1.88mmol/L和5.14mmol/L;选择性透过实验表明膜中形成了与5R-5氨-基酸海因分子形状和功能基因位置匹配的孔穴。与非印迹聚合物膜相比,印迹聚合物膜对对映体具有良好的选择性。     

香豆素-3-羧酸分子印迹聚合物复合膜对底物的结合及渗透选择性质的研究

在光照和引发剂的作用下, 模板分子香豆素-3-羧酸、 功能单体丙烯酰胺和交联剂乙二醇二甲基丙烯酸酯(EDMA)或三甲氧基丙烷三甲基丙烯酸(TRIM)在聚偏氟乙烯(PVDF)微孔滤膜表面聚合形成分子印迹聚合物复合膜. 用高效液相色谱仪测定了分别以TRIM和EDMA为交联剂制备的分子印迹聚合物膜在不同溶剂中对混合底物的结合和渗透选择性. 结果表明, 以TRIM为交联剂的印迹膜对模板分子具有更高的结合和渗透选择性. 另外, 以乙腈或乙腈/水作为溶剂对分子印迹膜所作的实验和讨论有助于为从复杂样品中分离模板分子奠定理论和实验基础.     

分子印迹手性分离过程的热力学研究

以丙烯酰胺为功能单体, 以二甲基丙烯酸乙二醇酯为交联剂, 在模板分子N-叔丁氧羰酰-L-色氨酸(N-Boc-L-Trp)和N-叔丁氧羰酰-L-酪氨酸(N-Boc-L-Tyr)的存在下, 分别采用光引发聚合和热引发聚合制备了N-Boc-L-Trp和N-Boc-L-Tyr的分子印迹聚合物(MIPs), 进行分子印迹手性分离过程的热力学研究. 测定了分离过程的熵变、焓变和自由能变化. 结果显示, 在流动相中添加异丙醇或甲醇等强氢键竞争性溶剂时, 熵变对分离起到了主要作用, 而且分离过程中的溶剂化对分离的影响也非常大. 分子印迹聚合物对印迹分子和非印迹分子进行分子识别的主要作用是印迹聚合物与印迹分子匹配的三维空间结构.     

溶菌酶分子印迹聚合物膜的制备及其吸附性能

以溶菌酶为模板蛋白质，结合分子印迹技术在硅烷化的基质玻片上制备了溶菌酶分子印迹聚合物膜。实验优化了溶菌酶聚合物膜的印迹体系，考察了溶菌酶分子印迹聚合物膜的吸附平衡时间、最大吸附量、特异识别能力、重复使用性以及对实际样品中溶菌酶的分离情况。结果表明，在最优条件下，制备的分子印迹聚合物膜对溶菌酶具有特异吸附能力，印迹因子为3.0，吸附平衡时间为5 min，吸附行为符合Langmuir吸附模型，理论最大吸附量为42.5 mg/g，实际样品中的吸附量为30 mg/g。且此印迹聚合物膜在重复使用5次后，最大吸附量仅下降了5%，具有良好的重复使用性。该方法为复杂生物样品中目标蛋白质的分离富集提供了一种快速、高效的手段。     

氟哌酸分子印迹共混膜的制备及结构表征

以氟哌酸为模板分子,α-甲基丙烯酸为功能单体,三甲氧基丙烷三甲基丙烯酸酯为交联剂,利用本体聚合方法制备了具有特异选择性的氟哌酸分子印迹聚合物,并利用聚砜与氟哌酸分子印迹聚合物共混的方法制备了分子印迹聚合物膜.运用红外光谱分析和透射电子显微镜研究了氟哌酸分子印迹聚合物的结构.运用扫描电子显微镜研究了分子识别膜的机理和吸附性能,运用平衡结合实验法证明了分子识别膜对氟哌酸表现出了较高的选择性.     

柚皮苷分子印迹膜的水相制备与识别

以柚皮苷为印迹分子,PEG为致孔剂,在水相中制备了柚皮苷分子印迹壳聚糖膜.分别讨论了交联剂、致孔剂和印迹分子的用量对印迹膜结构和性能的影响.用SEM观察了致孔剂对印迹膜形貌及孔径的影响.紫外吸收光谱分析、柚皮苷在不同体系中的溶解度变化,以及红外光谱分析的结果表明功能聚合物壳聚糖和模板分子柚皮苷间形成了氢键.膜的渗透实验结果表明,在水相中,柚皮苷分子印迹膜能有效地从新橙皮苷和柚皮苷的混合液中分离出印迹分子柚皮苷,选择透过率为11.16%.     

Preparing molecularly imprinted membranes by phase inversion to separate kaempferol

Molecularly imprinted membranes (MIMs) were studied to separate special target molecule – kaempferol, an important active pharmaceutical ingredient. The kaempferol MIM were prepared by the liquid–solid phase inversion method. The effects of polyphenylene sulfone, LiCl, and ZnCl₂ on membrane performance were studied, a high Flux MIM was prepared, then the kaempferol molecularly imprinted polymer membrane, non‐molecularly imprinted membrane, and non‐molecularly imprinted polymer membrane were prepared to investigate adsorption capacity. From adsorption isotherm curve, the maximum equilibrium adsorption quantity was 890 µg/g, and it was MIM. The MIM and molecularly imprinted polymer membrane give high selectivity towards kaempferol; the non‐molecularly imprinted membrane and non‐molecularly imprinted polymer membrane showed low adsorption quantity and selectivity. The reuse experiment of the MIM indicated that it has good reuse property. All the results showed binding sites were important in the separation process of MIMs. Copyright © 2016 John Wiley & Sons, Ltd.     

替代模板分子印迹技术在样品前处理中的应用

分子印迹聚合物具有抗恶劣环境、选择性高、稳定性好等特点,广泛应用于复杂样品的前处理。采用结构类似物作为替代模板分子,可以解决分子印迹聚合物制备时目标物溶解性差的问题,替代模板分子印迹聚合物不仅对目标分析物具有选择性识别能力,还可以避免模板泄露对痕量分析造成的影响。本文综述了替代模板分子印迹技术在样品前处理中的应用进展,包括替代模板分子印迹技术在固相萃取、固相微萃取、色谱固定相、基质固相分散萃取中的应用,最后对替代模板分子印迹技术在未来的样品前处理中的研究进行了展望。     

分子印迹膜萃取结合高效液相色谱-串联质谱法快速检测牛奶中的痕量环丙沙星残留

以聚偏氟乙烯膜为载体,恩诺沙星为伪模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在氯仿-甲醇混合体系中制备恩诺沙星分子印迹膜(MIM),并将其作为分子印迹膜萃取(MIME)材料萃取牛奶样品中的环丙沙星,结合高效液相色谱-串联质谱(HPLC-MS/MS),快速检测牛奶中痕量环丙沙星残留。环丙沙星在0.1～200μg/L范围内线性关系良好,相关系数为0.999 6,检出限(S/N=3)和定量限(S/N=10)分别为0.02和0.10μg/L。日间和日内精密度的相对标准偏差(RSD)在3.3%～7.9%之间。将开发的MIME-HPLC-MS/MS方法用于实际牛奶样品中环丙沙星加标回收率的检测,回收率在92.6%～119.1%之间。结果表明该方法前处理简单快速灵敏,检测准确度高,可用于牛奶样品中痕量环丙沙星残留的快速检测。     

Molecular imprinted membrane based on molecular imprinted nanoparticles polymer for separation of polycyclic aromatic hydrocarbons

The phase inversion technique was used for synthesis anthracene molecularly imprinted membrane (An–MIM) by hybridizing anthracene molecularly imprinted nanoparticles polymer (An–MINP) with cellulose acetate (CA). An–MIM gives high binding capacities toward anthracene, naphthalene, pyrene, benzo(a)pyrene, phenanthrene, and acenaphthylene. Meanwhile, cellulose acetate membrane (CAM) and none imprinted membrane give very low binding capacities toward Anthracene, Naphthalene, Pyrene, Benzo(a)pyrene, Phenanthrene and Acenaphthylene. The separation properties of An–MIM, none imprinted membrane (NIM), and CAM were investigated in terms of selectivity, rejection percentages, and concentrating factor. The optimum operation time of An–MIM was found to be 3 hr. The overall results indicated that the presence of chemical binding sites in the An–MIM plays predominating role in the separation properties. Therefore, An–MIM proved to be highly efficient for the removal of polycyclic aromatic hydrocarbons at various percentages. Copyright © 2015 John Wiley & Sons, Ltd.     

Towards the development of a portable sensor based on a molecularly imprinted membrane for the rapid determination of salbutamol in pig urine

A new type of conductometric probe based on a molecularly imprinted membrane (MIM) for the detection of salbutamol has been designed and fabricated. The probe consists of two parallel screen-printed electrodes (SPE). One of the SPEs was coated with a molecularly imprinted membrane using salbutamol as the template, and the other was modified with a non-molecularly imprinted membrane (N-MIM). Measurements of salbutamol were conducted after the conductometric probe had been connected to a commercial portable conductometer. Multi-sample or successive detections could be easily accomplished by replacing the one-off SPE coated with the salbutamol molecularly imprinted membrane with a new one. The conductometric response of the sensor to the concentration of salbutamol displayed a linear correlation over a range from 50 to 280 nM, with a detection limit of 13.5 nM. The recoveries reached 92.1-98.3% based on pig urine samples. In addition, the sensor based on this new type of probe demonstrated high sensitivity and selectivity for salbutamol.     

基于N,O-双异丁烯酰乙醇胺为交联功能单体的苯磺隆分子印迹聚合物膜的制备及其性能研究

以苯磺隆为模板分子, N,O-双异丁烯酰乙醇胺为交联功能单体, 在尼龙-6膜上通过紫外光照引发合成了分子印迹聚合物膜, 并用扫描电镜对其表面形态进行了表征. 用紫外分光光谱法研究了模板分子与交联功能单体之间的相互作用. 印迹因子的测定和底物竞争渗透实验结果表明, 分子印迹聚合物膜对模板分子苯磺隆具有较高的选择性, 而非分子印迹聚合物膜没有选择性.     

Transport Selectivity of a Diethylene Glycol Dimethacrylate- Based Thymine-imprinted Polymeric Membrane over a Cellulose Support for Nucleic Acid Bases

The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support. Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane, recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.