分子印迹固相萃取/毛细管电泳法同时测定水中酚

采用悬浮聚合方法合成了分子印迹高分子微球,建立了分子印迹固相萃取/毛细管电泳同时测定水样中苯酚、间苯二酚和对硝基苯酚的新方法。在优化的固相萃取条件下,模板分子获得了95%的吸附率和较高的富集倍数(33倍)。在一定浓度范围内3,种酚均呈现良好的线性关系(r≥0.999 2),方法检出限为0.048 8～0.809μg/kg,回收率为87.2%～100.4%,日内(n=5)、日间(n=3)精密度(RSD)分别为(1.89%～5.63%)(、6.91%～8.14%)。该方法简便、快速、准确,适用于环境水中酚类物质的测定。     

Encapsulation of quantum dots and carbon nanotubes with polypyrrole in a syringe needle for automated molecularly imprinted solid phase pre-concentration of ochratoxin A in red wine analysis

Nanometer-sized semiconductor quantum dots (QDs with CdSe core and ZnS shell) and carbon nanotubes (CNTs with multi-walls) were encapsulated inside a stainless steel syringe needle by electrodeposition of polypyrrole (PPy). By cross-linking the PPy with ethylene glycol dimethacrylate (EGDMA) in the presence of ochratoxin A (OTA) as a template, molecularly imprinted polypyrrole (MIPPy) was formed on the nano-hybrid structure at an increased specific surface area. The MIPPy/CNTs/QDs-modified needle was readily adapted in an autosampler for micro-solid phase preconcentration (μSPP) of OTA from a red wine sample. After pulsed elution (PE) with 2% triethylamine (TEA), the OTA was determined by high performance liquid chromatography (HPLC) with fluorescence detection (FD). In comparison with MIPPy/CNTs, this new nano-hybrid structure of MIPPy/CNTs/QDs significantly improved the % recovery of OTA. The method, MIPPy/CNTs/QDs-μSPP-HPLC-FD, demonstrated that the MIPPy was truly a molecularly imprinted polymer (MIP) with specific recognition for OTA. All red wine matrix components could be differentially washed out, prior to accurate determination of the strongly bound OTA.     

Study on preparation of protein‐imprinted soft‐wet gel composite microspheres with magnetic susceptibility and their characteristics. I. Preparation and particle morphology

Protein‐imprinted soft‐gel composite microspheres with magnetic susceptibility (MS‐PIGMs) were prepared by inverse suspension polymerization, using Fe₃O₄ particles as magnetically susceptible component, acrylamide (AM) and N,N′‐methylenebisacrylamide (BisAM) as polymeric matrix components, toluene as solvent, and bovine serum albumin (BSA) and lysozyme (Lyz) as templates, respectively. The surface morphology of MS‐PIGMs was observed by environmental scanning electron microscope (ESEM) and scanning electron microscope (SEM). The effects of the kinds and amount of dispersants, stirring rate, the amount and adding methods of initiator, the amount of Fe₃O₄ and monomer concentration on particle morphology of MS‐PIGMs, as well as the effects of crosslinking degree on swelling ratio and particle morphology in wet condition were investigated in detail. ESEM and SEM photographs showed that the resulting MS‐PIGMs were all spheroid form and had large quantity of regularly distributed pores in wet condition, which close in dry condition, and the experimental results indicated that all the affecting factors had obvious effects on particle morphology of MS‐PIGMs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 684–694, 2006     

Electrochemical sensors based on conducting polymer—polypyrrole

Conducting polymers can be exploited as an excellent tool for the preparation of nanocomposites with nano-scaled biomolecules. Polypyrrole (Ppy) is one of the most extensively used conducting polymers in design of bioanalytical sensors. In this review article significant attention is paid to immobilization of biologically active molecules within Ppy during electrochemical deposition of this polymer. Such unique properties of this polymer as prevention of some undesirable electrochemical interactions and facilitation of electron transfer from some redox enzymes are discussed. Recent advances in application of polypyrrole in immunosensors and DNA sensors are presented. Some new electrochemical target DNA and target protein detection methods based on changes of semiconducting properties of electrochemically generated Ppy doped by affinity agents are introduced. Recent progress and problems in development of molecularly imprinted polypyrrole are considered.     

全自动固相萃取净化-高效液相色谱法测定食用植物油中苯并(a)芘含量

为提高工作效率,降低误差,建立分子印迹柱全自动固相萃取净化-高效液相色谱法测定食用植物油中苯并(a)芘含量的方法。样品经正己烷提取,采用全自动固相萃取仪进行分子印迹柱净化,C18色谱柱分离,高效液相色谱-荧光检测器检测。结果表明：苯并(a)芘在0.5～20.0 ng/mL质量浓度范围内与峰面积线性关系良好,相关系数为0.999 9,方法检出限为0.09μg/kg,定量限为0.30μg/kg,加标回收率为91.7%～111.8%,相对标准偏差为2.0%～8.2%,与国标方法的检测结果不存在显著性差异;对市售38份食用植物油样品进行检测发现,苯并(a)芘的检出率为76.3%。该方法准确度高、重复性好,可批量自动化前处理样品,提高工作效率,并降低人员操作误差风险,适用于食用植物油中苯并(a)芘含量的测定。     

N-水杨酰苯胺分子印迹聚合物的制备及识别性能研究

采用分子印迹技术,以N-水杨酰苯胺为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,在甲醇溶液中制备了N-水杨酰苯胺分子印迹聚合物。用平衡吸附及高效液相色谱的方法对聚合物进行了评价,结果表明印迹聚合物对N-水杨酰苯胺有较强的亲和性和良好的选择性。     

四溴双酚A分子印迹聚合物的制备及其吸附机制初探

采用分子印迹技术,以四溴双酚A为模板分子、2-乙烯吡啶为功能单体、乙二醇二甲基丙烯酸酯为交联剂。通过本体聚合法合成了对四溴双酚A具有高度选择性的印迹聚合物。平衡吸附实脸表明：与空白聚合物相比,四溴双酚A印迹聚合物具有较高的吸附能力和选择识别能力。同时比较了印迹聚合物对模板分子和结构相似物的识别能力。结果表明印迹聚合物对四溴双酚A具有更好的特异选择性和识别能力,为复杂介质中四溴双酚A的富集检测提供了一种快速准确有效的方法。     

Adsorption characteristics of Cr(III) ionic imprinting polyamine on silica gel surface

In this paper, a kind of ionic imprinting polyamine (IIP) was prepared through an advanced approach. Firstly, functional macromolecule polyethyleneimine (PEI) was grafted onto the surfaces of silica gel particles, and the PEI/SiO₂ was formed. Secondly, the ionic imprinting process was carried out using Cr³⁺ ion as a template, and epichlorohydrin (ECH) as a crosslinking agent, and Cr³⁺ ionic imprinting polyamine IIP-PEI/SiO₂ was prepared. The adsorption properties of IIP-PEI/SiO₂ for Cr³⁺ ion were studied in details by adopting both static and dynamic methods, and the effects of main imprinting conditions, such as the concentrations of Cr(III) ion and the amount of ECH, on the adsorption property of the imprinted material IIP-PEI/SiO₂ were examined. The experimental results show that the IIP-PEI/SiO₂ has high affinity and excellent selectivity for the template ion. Its adsorption amounts for template ion enhances nearly two times compared to PEI/SiO₂, and its relative selectivity coefficients relative to Zn²⁺ and Pb²⁺ are 24.63 and 59.32 respectively. Besides, the IIP-PEI/SiO₂ has a fine elution property using HCl solution as eluent.     

不同制备条件对SpA分子印迹聚合微球聚合效果的影响

本文用金黄色葡萄球菌蛋白A(SpA)作为模板,以丙烯酰胺为功能单体,利用反相悬浮聚合法合成了SpA分子印迹聚合微球.通过扫描电镜观测不同条件下聚合微球的聚合效果,研究不同制备条件对SpA分子印迹聚合微球聚合效果的影响,从而筛选制备聚合微球最佳工艺;并检测了制备的分子印迹聚合物对SpA的吸附性能.结果表明,反相悬浮聚合法合成SpA分子印迹微球的最佳工艺条件为:分散剂乙基纤维素(EC)加入量0.20 g/100 mL(甲苯);甲苯与水的比例10:3;交联度10%;引发剂加入方式为缓慢滴加;反应温度50℃.反相悬浮聚合法制备的SpA分子印迹聚合微球对SpA的吸附量:6.956×10-3μmol/g.     

分子印迹电化学传感器检测链霉素

为实现链霉素的快速、灵敏测定,将特异性强的分子印迹技术与检测灵敏度高的电化学检测方法结合,构建链霉素分子印迹电化学传感器。以链霉素为模板分子,吡咯为功能单体,利用电化学聚合方法制备分子印迹聚合物(MIP)膜。在最优化实验条件下,以铁氰化钾为探针,利用循环伏安法(CV)对链霉素进行定量测定及传感器性能研究。结果表明:传感器线性范围为5.00×10~(-8)～8.00×10~(-5)mol/L,最低检出限(LOD)为3.45×10~(-8)mol/L,为链霉素的测定提供了高效的方法。