新型分子印迹电化学传感器的制备及其对农药残留检测性能的研究

发布时间：2018-05-08 08:09

本文选题：吡虫啉 + 噻虫嗪　；参考：《浙江工业大学》2017年硕士论文

【摘要】：现如今,农药被人们广泛使用,农药在改善农业的同时也引发了严重的农药残留问题,该现状时刻威胁着环境安全和人体健康。人们试图缓解现状,其中了解残留状况为前提,检测分析农药残留是关键。因此,开发高效简便的农药残留检测方法迫在眉睫,本文针对该情况,制备出对相应农药具有特异选择识别能力的分子印迹电化学传感器,进而检测分析残留情况。本论文主要研究内容分为以下两个部分:1.以壳聚糖为功能基体,吡虫啉(Imidacloprid,简称IMI)/噻虫嗪(Thiamethoxam,简称TMX)为模板分子,戊二醛为交联剂,应用恒电位沉积法制备分子印迹电极(经羧基化碳纳米管修饰)后构建IMI印迹传感器(IMI-MIP/F-CNTs/GCE)及TMX印迹传感器(TMX-MIP/F-CNTs/GCE)。并利用循环伏安法(CV)、差分脉冲伏安法(DPV)、交流阻抗谱(EIS)等电化学方法考察新型传感器对IMI/TMX的检测性能并构建等效电路模型。结果表明:成功地制备了新型分子印迹电化学传感器IMI-MIP/F-CNTs/GCE和TMX-MIP/F-CNTs/GCE;两个电极的表观表面积与裸电极相比显著提高,且都具有良好的印迹效果,成功制备的传感器对模板分子IMI/TMX的选择识别性能良好。同时建立了电路模型R1(CPE1(R2(CPE2(R3)))),该模型与交流阻抗谱等效,通过对电路模型各元件参数的计算,证明了传感器检测IMI/TMX的传感机理可以被此等效电路有效模拟。2.用农药(吡虫啉、噻虫嗪)对IMI-MIP/F-CNTs/GCE和TMX-MIP/F-CNTs/GCE进行抑制,然后用差分脉冲伏安扫描未抑制和已抑制的传感器,记录峰电流数据,计算抑制率,分析数据,同时做平行实验,以此来检测传感器对农药(吡虫啉、噻虫嗪)的响应性能及传感器的稳定性能。结果表明:IMI-MIP/F-CNTs/GCE及TMX-MIP/F-CNTs/GCE分别对目标分子IMI和TMX具有特异选择识别性能,且选择性能良好,同时电位沉积法制备的传感器稳定性良好,寿命长。制备得到的分子印迹电化学传感器对农药残留的检测、去除都具有非常重要的意义,并为传感器应用于其他领域提供了一定的参考依据。
[Abstract]:Nowadays, pesticides are widely used, which not only improve agriculture, but also cause serious pesticide residue problems, which always threaten environmental safety and human health. People try to alleviate the status quo, among which understanding the residual status is the premise, detection and analysis of pesticide residues is the key. Therefore, it is urgent to develop an efficient and simple method for the detection of pesticide residues. In this paper, a molecularly imprinted electrochemical sensor with specific ability to select and recognize pesticides was prepared to detect and analyze the residues. This thesis is divided into two parts: 1. Chitosan as functional matrix, imidaclopridine (IMI)/) as template molecule, glutaraldehyde as crosslinking agent. Molecularly imprinted electrodes (modified by carboxylated carbon nanotubes) were prepared by potentiostatic deposition method and IMI imprinting sensors IMI-MIP / F-CNTs / GCES and TMX imprinted sensors TMX-MIP / F-CNTs / GCES were constructed. Electrochemical methods such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and AC impedance spectroscopy (EIS) were used to investigate the performance of the new sensor and to construct an equivalent circuit model. The results show that the novel molecularly imprinted electrochemical sensors (IMI-MIP/F-CNTs/GCE and TMX-MIP / F-CNTs / GCE) have been successfully fabricated. The apparent surface area of the two electrodes is significantly higher than that of the bare electrode, and both have good imprinting effect. The successfully prepared sensor has good performance in the selection and recognition of template molecule IMI/TMX. At the same time, the circuit model R1 / CPE1 / R2 / CPE2 / R3 is established, which is equivalent to AC impedance spectrum. By calculating the parameters of each component of the circuit model, it is proved that the sensing mechanism of the sensor for detecting IMI/TMX can be effectively simulated by the equivalent circuit. IMI-MIP/F-CNTs/GCE and TMX-MIP/F-CNTs/GCE were inhibited by pesticides (imidacloprid, thiamethazine), and then the uninhibited and suppressed sensors were scanned by differential pulse voltammetry. The peak current data were recorded, the inhibition rate was calculated, and the data were analyzed. The response of the sensor to pesticides (imidacloprid, thiamizine) and the stability of the sensor were measured. The results show that: IMI-MIP / CNTs / GCE and TMX-MIP/F-CNTs/GCE have special selective recognition performance for target molecules IMI and TMX respectively, and the selectivity is good. Meanwhile, the sensor prepared by the potential deposition method has good stability and long lifetime. The prepared molecularly imprinted electrochemical sensors are of great significance for the detection and removal of pesticide residues and provide a reference for the application of the sensors in other fields.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1;TQ450.263

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