【作者】 薛瑞；

【导师】 康天放；

【作者基本信息】 北京工业大学 ， 环境科学， 2014， 博士

【摘要】 我国是一个农业大国，也是农药生产和使用的大国。随着农业的发展，农药残留所引发的环境污染和食品安全问题逐渐引起了人们的重视。发展农药残留检测技术，尤其是快速检测技术，对及时监控环境和食品中的农药残留具有重要意义。电化学传感技术是农药残留快速检测技术中的一种重要方法。根据检测原理的不同，又可分为化学传感器、酶生物传感器和免疫传感器等。近年来随着纳米科技的发展，利用纳米材料的特性来构建快速、高效、灵敏以及适合现场检测的电化学传感器已成为农药残留快速检测技术的研究发展方向。本文通过对石墨烯、碳纳米管、贵金属纳米粒子、磁性纳米粒子等新型纳米材料电化学催化活性的考察，针对不同的传感器，选择合适的纳米材料来构建传感器界面，以期制得灵敏度高、选择性好、响应快、稳定性好的电化学传感器。主要研究内容包括：(1)以石墨烯-Nafion复合物作为固相吸附剂，修饰玻碳电极(Graphene-Nafion/GCE)，制备用于检测有机磷农药的溶出伏安电化学传感器。采用改进的Hummers化学法制备氧化石墨和石墨烯，并且利用X射线光电子能谱对其进行了表征。分别采用扫描电子显微镜和循环伏安法、方波伏安法考察了修饰电极的表面形貌特征和电化学特性。在优化实验条件下，考察该传感器对甲基对硫磷检测的线性范围和检出限，并进一步将其应用于实际样品的测定。(2)以丝素蛋白(SF)为载体，通过非共价吸附将乙酰胆碱酯酶(AChE)固定在修饰了多壁碳纳米管(MWNTs)的玻碳电极上，制备用于检测有机磷和氨基甲酸酯类农药的酶生物传感器AChE-SF/MWCNTs/GCE。通过原子力显微镜考察了修饰电极表面的形貌特征。采用安培法研究了乙酰硫代胆碱在该生物传感器上的电化学行为。在优化的实验条件下，建立了响应的分析方法，并将该酶传感器应用于蔬菜样品中甲基对硫磷的检测。(3)采用层层自组装技术制备了快速检测有机磷农药的生物传感器，利用带正电荷的高分子聚电解质聚二烯丙基二甲基氯化铵(PDDA)将AChE和金纳米粒子(AuNPs)通过静电力逐层固定到玻碳电极表面，利用扫描电子显微镜、交流阻抗和微分脉冲伏安法分别考察了修饰电极的形貌特征以及电化学特性。考察酶传感器对甲基对硫磷检测的线性范围和检测限，并将其进一步应用于实际样品的测定。(4)采用化学共沉淀技术制备磁性纳米粒子复合物Fe3O4-AuNPs，并以此磁性纳米复合物构建用于快速检测有机磷农药的酶生物传感器。通过磁力作用将Fe3O4-AuNPs纳米粒子固定在自制的磁性玻碳电极(MGCE)上，并以此作为AChE的载体。分别通过X射线衍射、振动样品磁强和透射电镜表征了磁性纳米粒子复合物Fe3O4-AuNPs的成分、磁性及其形貌特征。利用电化学阻抗、循环伏安法和差分脉冲伏安法表征了自制磁性玻碳电极以及修饰好的酶传感器(AChE/Fe3O4-AuNPs/CNTs/MGCE)的电化学特征。考察了该酶传感器对于对氧磷检测的线性范围和检测限，并将其进一步应用于实际样品的测定。(5)采用竞争免疫分析法，基于半抗原对抗体的反应原性，建立了快速检测除草剂2,4-二氯苯氧基乙酸(2,4-D)的电化学免疫分析方法。将半抗原自组装在烷基化的玻碳电极上，与分析物竞争吸附酶标抗体。优化免疫传感器的实验条件。将免疫传感器应用于实际水样的测定。更多还原

【Abstract】 China is a large country for agricultural, and it is also a large country for pesticideproduction and use. With the development of agriculture, people pay more attention tothe environmental pollution and food safety problems caused by pesticide residues. Ithas important significance to develop the detection technology, especially the rapiddetection technology for monitoring pesticide residues in environment and foodtimely.Electrochemical sensing technology is an important method for rapid detection ofpesticide residues. According to different detection principle, electrochemical sensorcan be divided into chemical sensor, biosensor and immunosensor, etc. In recent years,with the development of nanoscience and nanotechnology, it has become the directionof research to construct the electrochemical sensor interface with the characteristics offast, efficient, sensitive and suitable for field detection pesticide residues by nanomaterials. In this paper, the electrochemical sensors with the character of highsensitivity, selective, fast response, good stability were constructed by selecting theappropriate nano materials. The sensor interface was fabricated through theinvestigation of the electrochemical catalytic of graphene, carbon nanotubes, noblemetal nanoparticles and magnetic nanoparticles. The main research contents are asfollows:(1) A graphene-Nafion matrix which was used as solid-phase adsorbents modifiedglassy carbon electrode (Graphene-Nafion/GCE) was developed for the determinationof organophosphorus pesticides. Graphene nanosheets was synthesized chemically byHummers method, and characterized by X-ray photoelectron spectroscopy. Thesurface morphology and electrochemical properties of the Graphene-Nafion/GCEwere investigated by means of scanning electron microscopy, cyclic voltammetry, andsquare-wave voltammetry, respectively. Under the optimized experimental conditions,took methyl parathion as a model compound, the linear range and the detection limitof the electrochemical sensor were investigated. Furthermore, theGraphene-Nafion/GCE was applied in the determination of real samples.(2) An amperometric biosensor for the determination of organophosphate andcarbamate pesticides was developed based on the immobilization ofacetylcholinesterase(AChE) on regenerated silk fibroin(SF) matrix by non-covalentadsorption. The obtained biosensor was denoted as AChE-SF/MWNTs/GCE. Thesurface morphology of biosensor was characterized by the atomic force microscopyimages. The electrochemical behavior of acetylthiocholine was investigated byamperometry. Under the optimized experimental conditions, a new method was established and applied in the determination of methyl parathion in vegetable samples.(3) An amperometric biosensor for the rapid determination of organophosphoruspesticide was developed based on layer by layer self-assembly both AChE and goldnanoparticles(AuNPs) on GCE in the presence of poly(diallyldimethylammoniumchloride)(PDDA). The morphological characteristics and electrochemical propertiesof the biosensor were investigated by scanning electron microscope, electrochemicalimpedance spectroscopy and differential pulse voltammetry. Took methyl parathion asa model compound, the linear range and the detection limit of the biosensor wereinvestigated. The biosensor was applied in the determination of real samples.(4) An amperometric biosensor for the rapid detection of organophosphoruspesticide was developed based on magnetic nanoparticle complexes Fe3O4-AuNPsprepared by chemical co-precipitation. These magnetic nanoparticle complexes wereimmobilized on a homemade magnetic glassy carbon electrode and served as matrixfor immobilizing AChE. The chemical composition of magnetic properties andmorphology of magnetic nanoparticles composite Fe3O4-AuNPs were characterizedby X-ray diffraction, vibrating sample magnetometry and transmission electronmicroscopy. The electrochemical characteristics of home-made magnetic glassycarbon electrode and enzyme biosensor were characterized by electrochemicalimpedance spectroscopy and cyclic voltammetery, differential pulse voltammetry. Byparaoxon as an example, the detection linear range and detection limit of the pesticideon enzyme biosensor were investigated. This biosensor was also applied to thedetermination of the pesticide in real samples.(5) A fast, simple and sensitive electrochemical competitive immunosensingmethod was developed to monitor herbicide,2,4-dichlorophenoxyacetic acid(2,4-D)based on the specific recognition between hapten and labeled antibody. The hapten2,4-D self-assembled on the alkylation GCE competed with analyte forenzyme-labeled antibody binding. The analyte concentration was dependent on theelectrochemical signal of enzyme-labeled antibody adsorbed on the GCE by hapten.The performance of the immunosensor was evaluated on river water samples spikedwith2,4-D.更多还原