基于纳米材料增敏技术的β-受体激动剂分子印迹传感器的研究

发布时间：2019-01-30 13:06

【摘要】：β-受体激动剂类药物在畜牧生产中具有促进动物生长及减少脂肪沉积的作用,但其易在动物体内残留,影响动物产品安全并危害人类健康。目前我国对此类药物的监管是先使用免疫速测技术对样品进行筛查,而后对可疑样品进行仪器确证分析。免疫速测技术易出现假阳性和假阴性,仪器确证前处理时间长,因此有必要开发高效灵敏的分析技术以满足对此类药物的分析要求。分子印迹传感器能够结合分子印迹聚合物专一性吸附的特性及传感器快速灵敏分析的特点,提高了检测分析效率,但也存在对β-受体激动剂等小分子物质分析检测信号响应差,灵敏度不足的缺点。纳米材料具有比表面积大和表面反应活性高等特点,可作为分子印迹传感器的增敏材料。基于此,本研究中将分子印迹技术与纳米技术相结合,通过不同方式修饰纳米材料和印迹聚合物,得出了以下结论:(1)采用石墨烯/纳米金杂化纳米材料修饰玻碳电极,在此基础上以邻苯二胺为功能单体,莱克多巴胺为模板分子,采用电聚合法制备了分子印迹电化学传感器。研究结果表明,当石墨烯采用滴涂法、纳米金采用电聚合法;聚合介质为乙酸铵缓冲液(pH=5.2),聚合电位为0-2.0V,聚合圈数为10圈,模板与功能单体比例为1:3,模板洗脱溶液为pH=7.0PBS且采用电洗脱的方式时,可以制得性能较好的分子印迹传感器。在优化后的条件下进行分析时,检测限为0.0244ng/mL,尿液基质回收率高于80%。研究制得的纳米材料分子印迹传感器比同类电化学传感器有着更高的灵敏度,石墨烯纳米金能够对分子印迹传感器起到增敏作用。(2)在现有文献报道基础上通过优化交联剂和致孔剂的用量制备了莱克多巴胺分子印迹聚合物微球,结合石墨烯/纳米金复合纳米材料采用直接旋涂法制备得到分子印迹SPR传感器。结果显示,制得的SPR传感器表面分子印迹聚合物及复合纳米材料能够均匀分布,且厚度适中;使用PBS(pH=7.0)为缓冲溶液,样品溶剂为PBS/乙腈(体积为9:1),再生液为乙酸/乙腈(体积比为3:7)时,仅需780s即可完成单个样品分析过程,分析效率高,且对β-受体激动剂类药物SAL及CL有着良好的选择性和灵敏度,检出限可达5ng/mL。对比现有研究报道中分子印迹SPR传感器(检出限一般为20-50ng/mL),研究中使用的复合纳米材料能够显著的提高SPR传感器的灵敏度,可为其他小分子物质使用此传感器提供技术参考。本研究中,通过在玻碳电极和裸金芯片表面修饰石墨烯/纳米金及印迹聚合物制备出了具高选择性和高灵敏度、能够快速准确分析β-受体激动剂的分子印迹电化学传感器和分子印迹SPR传感器,并建立相应的分析方法,研究结果可为其他物质制备分子印迹传感器进行残留分析提供参考。
[Abstract]:尾-receptor agonists can promote animal growth and reduce fat deposition in animal husbandry, but it is easy to remain in animals, which affects the safety of animal products and endangers human health. At present, the supervision of this kind of drugs in our country is to screen the samples by immunological rapid detection technique, and then to analyze the suspicious samples by means of instrument. Rapid immunoassay is prone to false-positive and false-negative, so it is necessary to develop an efficient and sensitive analytical technique to meet the requirements of this kind of drug analysis. The molecular imprinting sensor can improve the efficiency of detection and analysis by combining the characteristics of molecular imprinted polymer specific adsorption and fast sensitive analysis of the sensor. However, there are also shortcomings of poor response and low sensitivity to small molecular substances such as 尾-receptor agonists. Nanomaterials with large surface area and high surface reaction activity can be used as sensitizing materials for molecular imprinting sensors. Based on this, the molecular imprinting technology and nanotechnology were combined in this study, and the following conclusions were obtained by modifying nano-materials and imprinted polymers in different ways: (1) the glassy carbon electrode was modified by graphene / nano-gold hybrid nanomaterials. The molecularly imprinted electrochemical sensor was prepared by electropolymerization with o-phenylenediamine as functional monomer and ractopamine as template molecule. The results show that when graphene is dripped, nano-gold is electropolymerized. When the polymerization medium is ammonium acetate buffer (pH=5.2), the polymerization potential is 0-2.0 V, the number of polymerization cycles is 10 cycles, the ratio of template to functional monomer is 1: 3, the template elution solution is pH=7.0PBS and the electroelution method is used. Molecular imprinting sensor with better performance can be prepared. The detection limit was 0.0244 ng / mL and the recovery rate of urine matrix was higher than 80%. The molecular imprinting sensor of nanomaterials has higher sensitivity than the electrochemical sensor of the same kind. Graphene nanocrystalline gold can enhance the sensitivity of molecular imprinting sensor. (2) based on the existing literature, ractopamine molecularly imprinted polymer microspheres were prepared by optimizing the amount of crosslinking agent and pore-inducing agent. The molecularly imprinted SPR sensor was prepared by direct spin-coating method combined with graphene / nano-gold composite nanomaterials. The results show that the molecularly imprinted polymers and composite nanomaterials on the surface of SPR sensors can be evenly distributed and the thickness is moderate. When PBS (pH=7.0) was used as buffer solution, the sample solvent was PBS/ acetonitrile (9:1 in volume) and the regenerated solution was acetic acid / acetonitrile (3:7), the single sample analysis process could be completed in 780s, and the analysis efficiency was high. It has good selectivity and sensitivity for 尾 -receptor agonists SAL and CL, and the detection limit is up to 5 ng / mL. Compared with the molecularly imprinted SPR sensor (the detection limit is generally 20-50ng/mL), the composite nanomaterials used in the study can significantly improve the sensitivity of the SPR sensor. It can provide technical reference for other small molecular matter to use this sensor. In this study, high selectivity and high sensitivity were obtained by modifying graphene / nanocrystalline and imprinted polymer on glassy carbon electrode and bare gold chip. Molecularly imprinted electrochemical sensors and molecularly imprinted SPR sensors can be used to analyze 尾-receptor agonists quickly and accurately, and the corresponding analytical methods are established. The results can provide a reference for the residue analysis of molecularly imprinted sensors prepared by other substances.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S859.84

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