基于分子印迹技术的农药远程监检QCM传感器研究

发布时间：2018-03-16 21:23

本文选题：农药　切入点：分子印迹　出处：《郑州大学》2016年硕士论文　论文类型：学位论文

【摘要】：农药在生产和生活中应用十分广泛。有相关统计显示全世界每年大约有200万人因农药污染而患病,工业排放的污水中农药超标、大棚蔬菜施药不当及施用违禁高毒农药对环境安全和人类身体健康造成极大威胁,成为亟待解决的重大社会问题。传统的农药检测手段大多设备昂贵、操作复杂,需要使用大量有机溶剂进行预处理,并且无法实时监测。目前,市场迫切需要能实现对工业废水、食品生产加工聚集区、农药生产和施用现场农药远程监检的方法。因此研究无需样品预处理,能简单、快速、实时地监检水中农药及农药喷施过程的检测手段具有十分重要的意义。本文首次提出并构筑了农药现场检测监控系统的理念和方法,并以制备简单、易于分离、特异性好的分子印迹聚合物为识别手段;以超灵敏、非标记性和能实时在线检测的石英晶体微天平为检测手段;以最常用的有机磷农药毒死蜱为模板分子,制备具有样品无需预处理,高特异性和高灵敏度,可直接检测水相以及蔬菜大棚喷雾中的毒死蜱乳油的功能的石英晶体微天平传感器,努力实现农药实施现场及农药污染源实施远程检测监控的设计目的。本课题的研究内容和结果具体包括以下三个方面:1.设计并通过电化学聚合方法以毒死蜱乳油为模板分子,吡咯为功能单体,磷酸盐缓冲溶液作溶剂,制备了毒死蜱分子印迹聚吡咯修饰的石英晶体微天平传感器,并对其制备条件进行了优化;通过电化学循环伏安、交流阻抗、静态水接触角、石英晶体微天平、扫描电子显微镜和原子力显微镜分别对聚吡咯印迹薄膜的性质及表面形貌进行了表征。2.通过毒死蜱聚吡咯印迹传感器测定毒死蜱乳油水溶液,同时制备的两个传感器检出限分别为1.30 ppm和1.72 ppm,表明传感器制备重现性良好。从特异性、温度稳定性、实际样品实验和再生性方面对传感器的性能进行分析。结果表明印迹传感器对毒死蜱乳油的检测是对毒死蜱分子的特异性识别,检测结果受温度影响较小,该传感器能检测蔬菜汁液等复杂基质中的毒死蜱,加标回收率92%~104%,相对标准偏差为4%,传感器可再生13次。此外,在水相检测时探索施加DEP对毒死蜱乳胶微粒进行富集,加快识别速率,降低检出限。3.首先采用聚吡咯毒死蜱印迹传感器对毒死蜱乳油喷雾进行测定,结果显示频率响应受水影响较大,与农药的浓度没有线性关系且特异性不好。继而选择强疏水性的聚偏氟乙烯(PVDF)作为成膜物质制备了PVDF毒死蜱印迹传感器,其测定农药喷雾有一定的特异性但仍未达到预期效果。进而又选择有机硅绝缘漆为成膜物质,从水接触角在酸洗后增大及扫描电子显微镜图中的大量微米亚微米凹槽推测其可能是形成了一种类荷叶的疏水结构。识别过程中共振频率变化呈锯齿状,可能是印迹位点包埋所致,也可能与凹槽中存有空气相关。
[Abstract]:Pesticide is widely used in production and daily life. Some statistics show that every year about 2 million people in the world get sick because of pesticide pollution. The improper application of pesticides in greenhouse vegetables and the application of banned high toxic pesticides pose a great threat to environmental safety and human health and become a major social problem to be solved urgently. Most of the traditional pesticide detection methods are expensive in equipment and complex in operation. Need to use a large number of organic solvents for pretreatment, and can not be monitored in real time. At present, the market urgently needs to be able to achieve industrial wastewater, food production and processing areas, Methods for remote monitoring and inspection of pesticides in the field of pesticide production and application. It is of great significance to monitor and inspect the pesticide and pesticide spraying process in water in real time. The idea and method of pesticide field detection and monitoring system are put forward and constructed for the first time in this paper, and the preparation is simple and easy to separate. Specific molecularly imprinted polymers are used as recognition methods; quartz crystal microbalance, which is hypersensitive, unlabeled and can be detected online in real time; chlorpyrifos, the most commonly used organophosphorus pesticide, as template molecule. A quartz crystal microbalance sensor with the functions of no pretreatment, high specificity and high sensitivity for direct detection of chlorpyrifos emulsifiable oil in vegetable greenhouse spray was prepared. The research contents and results of this paper include the following three aspects: 1.Design and use chlorpyrifos emulsifiable oil as template molecule by electrochemical polymerization method. Using pyrrole as a functional monomer and phosphate buffer solution as solvent, the imprinted polypyrrole modified quartz crystal microbalance sensor modified by chlorpyrifos was prepared and its preparation conditions were optimized. The properties and surface morphology of polypyrrole imprinted films were characterized by static water contact angle, quartz crystal microbalance, scanning electron microscope and atomic force microscope. 2. Chlorpyrifos emulsion aqueous solution was determined by chlorpyrrosine polypyrrole imprinting sensor. The detection limits of the two sensors were 1.30 ppm and 1.72 ppm, respectively, which indicated that the reproducibility of the two sensors was good. The results show that the detection of chlorpyrifos by imprinting sensor is a specific recognition of chlorpyrifos molecules, and the detection results are less affected by temperature. The sensor can detect chlorpyrifos in complex matrix, such as vegetable juice. The recovery rate of chlorpyrifos is 920.The relative standard deviation is 4. The sensor can regenerate 13 times. In addition, the application of DEP in water phase detection is explored to enrich chlorpyrifos latex particles. Firstly, the polypyrrole chlorpyrifos imprinted sensor was used to determine the chlorpyrifos emulsion spray. The results showed that the frequency response of chlorpyrifos was greatly affected by water. There was no linear relationship with the concentration of pesticides and the specificity was not good. Then the hydrophobic polyvinylidene fluoride (PVDF) was used as the membrane material to prepare PVDF chlorpyrifos imprinting sensor. The determination of pesticide spray has a certain specificity, but still does not reach the desired effect. Then, the silicone insulating paint is selected as the film forming material. Based on the increase of water contact angle after pickling and the large number of micron submicron grooves in the scanning electron microscope (SEM), it is speculated that the water contact angle may form a hydrophobic structure of a kind of lotus leaf. It may be caused by imprinting site entrapping, or it may be related to the existence of air in the grooves.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O631.3

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