【作者】 李娟；

【导师】 霍丹群；

【作者基本信息】 重庆大学 ， 生物医学工程， 2012， 硕士

【摘要】 农药在农业中占有举足轻重的地位，它在保证农产品产量和质量方面有着不可替代的作用。但是，农药的不合理使用导致的农药残留超标问题对食品安全、环境安全和对外贸易出口等方面有着不容忽视的危害，已成为世界共同关注的热点问题。因此，开发对农药残留进行快速、便捷和准确的检测方法，实现农药残留基层的实时快速检测非常必要。本文采用低成本、高灵敏、适用范围广、易于掌握推广的紫外可见分光光度法，引入光敏感材料卟啉对农药进行了检测，并初步探索了其检测机理。本论文的主要研究内容是：1.合成了用于农药残留检测的卟啉化合物。包括5-（4-羧基苯基）-10,15,20-三苯基卟啉（CTPP）、5-（4-羧基苯基）-10,15,20-三苯基卟啉锌（ZnCTPP）、5-（4-氨基苯基）-10,15,20-三苯基卟啉（ATPP）和5-（4-氨基苯基）-10,15,20-三苯基卟啉锌（ZnATPP），通过紫外、红外和核磁进行了表征确认。2.采用四种卟啉，通过紫外-可见分光光度法对有机磷农药毒死蜱、有机氯农药三唑酮、氨基甲酸酯农药多菌灵和拟除虫菊酯农药溴氰菊酯四类结构各异的农药进行了检测。得到了卟啉与农药作用的紫外光谱图、校准曲线、灵敏度及检测限。以农药残留的国家标准为基础，综合考虑线性关系对卟啉进行了筛选，结果表明ATPP、CTPP和ZnATPP适于对毒死蜱残留进行检测，检测限分别为1ppb、10ppb和10ppb； CTPP和ZnATPP适于对三唑酮残留进行检测，其检测限分别为1ppb和10ppb；CTPP和ATPP适于对多菌灵和溴氰菊酯残留进行检测，对多菌灵的检测限为0.1ppb和10pbb，对溴氰菊酯的检测限为0.1ppb和1ppb。3.采用Sybyl软件通过计算机模拟研究了ATPP、ZnATPP、CTPP和ZnCTPP与四类农药间的相互作用。结果表明，不同的卟啉对与同一种农药作用力大小不同。其中，CTPP与四种农药通过氢键和π-π堆积力进行作用，而其它三种卟啉与农药通过π-π堆积力进行作用，分子对接结果说明CTPP与四种农药的结合力最强，4．采用光谱法研究了CTPP与四种农药的相互方式、结合常数及热力学常数等。结果表明，CTPP作为电子受体，四种农药作为电子供体，二者通过氢键和π-π作用分别形成了1：1的配合物，其结合常数随着温度的升高而减小，低温利于配位反应的进行。在室温下，CTPP与毒死蜱、三唑酮、多菌灵和溴氰菊酯的结合常数分别为6.02×10²M^-1、6.44×10²M^-1、26.30×10²M^-1和27.30×10²M^-1，CTPP与多菌灵和溴氰菊酯的结合常数较大，说明它们的作用力较强。计算了CTPP与四种农药作用的标准摩尔的焓变（rHm^θ）和标准摩尔反应熵变（rSm^θ），表明CTPP与毒死蜱复合物的形成是一个熵降低的放热过程，而与其余三种农药反应是熵增加的放热反应过程。更多还原

【Abstract】 Pesticides play an irreplaceable role in agriculture to assure agricultural product inquality and quantity, but residues from pesticide abuse has become a worldwide issuebecause it is harmful to food, environment and export. To solve the problem, it isextremely urgent to develop a new method for pesticide residues detection with highsensitivity, rapidity and reliability. Based on its low cost, high sensitivity, wideapplicability and easy popularization, UV-Visable spectrometry association with highphotosensitive porphyrins was proposed to detect pesticide residues, and theirinteraction mechanism was initially discussed. Specifically, the thesis was completed asfollows:1. Four porphyrins including5-（4-carboxyphenyl）-10,15,20-triphenylporphyrin（CTPP）,5-（4-carboxyphenyl）-10,15,20-triphenylporphyrin zinc （ZnCTPP）,5-（4-aminophenyl）-10,15,20-triphenylporphyrin （ATPP） and5-（4-aminophenyl）-10,15,20-triphenylporphyrin zinc （ZnATPP） were synthesized for pesticide residues detection.Their structures were characterized by UV-Visible spectrophotometry, FT-IRspectrometry and1HNMR spectrometry.2. Four typical pesticides including organophosphorus chlorpyrifos,organochlorine triadimefon, carbamate carbendazim and pyrethroid decamethrin weredetected with four as-prepared porphyrins by UV-Visible spectrophotometry. Aftersystematic data processing, the absorance-concentration relationship, calibration curve,sensitivity and detection limit were obtained. Based on the national standard of pesticideresidues and linear relationship of the results, ATPP, CTPP and ZnATPP were selectedas the superior porphyrins to detect chlorpyrifos with detection limits of1ppb,10ppband10ppb, individually. Meanwhile, CTPP and ZnATPP were more suitable fortriadimefon with detection limits of1ppb and10ppb. CTPP and ATPP were not only fitfor carbendazim but also decamethrin with detection limits of0.1ppb,10ppb,0.1ppband1ppb, individually.3. Molecular interactions of porphyrins with pesticides were initially investigatedby molecular docking modul of Sybyl. The results showed CTPP was best for pesticidesdetection because of their interaction by hydrogen bonding and π-π facial stacking,while other three porphyrins only via π-π facial stacking. 4. Molecular interactions incluing association constants and themodynamicconstants of CTPP with four pesticides were studied by UV-Visible spectrophotometry.The results demonstrated CTPP as the electron receptor and pesticides as the electrondonor coordinated via hydrogen bonding and π-π facial stacking with coordinationnumber of1：1. Their association constants of CTPP with chlorpyrifos, triadimefon,carbendazim and decamethrin at298.15K were6.02×10²M^-1,6.44×10²M^-1,26.30×10²M^-1and27.30×10²M^-1, individually. And they decreased with temperatureincreased, which indicated lower temperature benefits to the reactions. However, it wasfound that CTPP showed stronger binding ability to carbendazim and decamethrinbecause of higher association constants. Moreover, the standard molar enthalpy change（rHm^θ） and standard molar entropy change （rSm^θ） of the four reaction systems wereinvestigated, which indicated chlorpyrifos coordinating with CTPP was a entropydecreased exothermic reaction, while other three pesticides with CTPP were entropyincreased exothermic reactions.更多还原