农药喷雾沉积量检测电化学传感系统研究
发布时间：2019-06-29 11:40
【摘要】：作为农业大国,农业发展中作物病虫害防治是保证农产品稳产增收的关键环节。喷洒化学药剂是应用最为普遍的防治措施,然而喷洒农药量不足不能有效杀死病虫害,喷洒农药量过大不仅造成资源浪费、环境污染,甚至威胁人类健康。目前喷雾沉积量检测大多采用水敏纸和实验室的光度法,然而这两种方法在一定程度上均存在一定的弊端。因此开发一种操作简便、价格低廉的便携式现场喷雾沉积量检测系统尤为重要。本文旨在电分析化学的基础上,研发出灵敏度高,选择性好,性能稳定的直接电化学传感器,通过设计信号处理电路硬件处理单元、信号显示软件处理单元、以及系统中电源电路关键,实现整体系统的构建,并对系统进行了性能分析实验。主要完成工作包括以下几个方面:(1)有机磷农药电化学传感器的构建及其性能研究。将氮掺杂石墨烯纳米材料修饰到丝网印刷电极表面,制备成对农药快速响应的敏感元件,构建了一种简单灵敏的无酶电化学传感器,用于农药甲基对硫磷的检测。采用扫描电子显微镜对敏感部位结构进行表征。通过利用循环伏安技术(CV)、差分脉冲伏安技术(DPV)、线性扫描伏安技术(LSV)来研究甲基对硫磷的电化学行为。由于氮掺杂结构和性质的独特性,氮掺杂石墨烯对PBS溶液中的甲基对硫磷产生较高的电催化活性。在信噪比为3的情况下,此传感器对甲基对硫磷的最高灵敏度为15.32μA/μmol。在优化条件下,制备的传感器具有较好的稳定性和选择性。(2)系统中信号检测关键单元的分析与设计。系统调理电路的硬件单元设计,包括恒电位电路设计、I/V转换放大电路、滤波电路以及电源电路设计.在12V直流电源能量供应下,将微安级电流信号转成0-2.5V范围内的模拟电压信号;对信号转换部分电路完成测试,确保得到预期功能效果,并得到输出电压与药液浓度之间的数量关系用于软件编程,检测灵敏度0.6V/μmol。完成信号显示单元的软件设计,选择控制芯片STC89C52、A/D转换芯片PCF8591以及1602液晶完成喷雾沉积质量浓度的数据显示,将模拟电压信号转成数字信号由单片机程序处理实现液晶显示。(3)系统整体结构性能测试与应用。完成检测系统整体结构的构建,并通过实际喷雾检测试验与电化学工作站检测结果相对比,对系统实际应用性能作数据分析,完成对系统准确度和稳定性的性能测试。系统应用于叶面喷雾沉积均匀性和整株喷雾沉积量分布的喷雾沉积量检测。该检测系统方法简单,较好的准确度和稳定性,且实现了小型便携化。确定了系统的稳定检出时间240s以及实际应用系统检测误差小于5%?在实际喷雾作业环境下,农药喷雾沉积量检测电化学传感系统表现出稳定好、便携式的优点,在现场喷雾沉积量监测中具有较好的应用前景。
[Abstract]:As a large agricultural country, the control of crop pests and diseases in agricultural development is the key link to ensure the stable yield and income of agricultural products. Spraying chemical agents is the most common control measure, however, the lack of spraying agricultural drugs can not effectively kill diseases and insect pests, spraying too much pesticides not only cause waste of resources, environmental pollution, and even threaten human health. At present, most of the spray deposition detection adopts water-sensitive paper and laboratory photometric method, however, to a certain extent, these two methods have some disadvantages. Therefore, it is very important to develop a portable field spray deposition detection system with simple operation and low price. The purpose of this paper is to develop a direct electrochemical sensor with high sensitivity, good selectivity and stable performance on the basis of electroanalytical chemistry. The hardware processing unit of signal processing circuit, the signal display software processing unit and the key of power supply circuit in the system are designed to realize the construction of the whole system, and the performance analysis experiment of the system is carried out. The main work includes the following aspects: (1) Construction and performance of organophosphorus pesticide electrochemical sensor. Nitrogen-doped graphene nanomaterials were modified on the surface of screen printing electrode to prepare sensitive elements for rapid response to pesticides. A simple and sensitive enzyme-free electrochemical sensor was constructed for the detection of pesticide methyl parathion. The structure of the sensitive part was characterized by scanning electron microscope (SEM). The electrochemical behavior of methyl parathion was studied by using cyclic volt-ampere technique (CV), differential pulse volt-ampere technique (DPV), linear scanning volt-ampere technique (LSV). Because of the unique structure and properties of nitrogen doping, nitrogen-doped graphene has high electrocatalytic activity for methyl parathion in PBS solution. When the signal-to-noise ratio (SNR) is 3, the maximum sensitivity of the sensor to methyl parathion is 15.32 渭 A / 渭 mol. Under the optimized conditions, the sensor has good stability and selectivity. (2) the analysis and design of the key units of signal detection in the system. The hardware unit design of the system conditioning circuit, including potentiostatic circuit design, I V conversion amplifier circuit, filter circuit and power supply circuit design. Under the energy supply of 12V DC power supply, the microampere current signal is converted into an analog voltage signal in the range of 0 鈮，
本文编号：2507789
[Abstract]:As a large agricultural country, the control of crop pests and diseases in agricultural development is the key link to ensure the stable yield and income of agricultural products. Spraying chemical agents is the most common control measure, however, the lack of spraying agricultural drugs can not effectively kill diseases and insect pests, spraying too much pesticides not only cause waste of resources, environmental pollution, and even threaten human health. At present, most of the spray deposition detection adopts water-sensitive paper and laboratory photometric method, however, to a certain extent, these two methods have some disadvantages. Therefore, it is very important to develop a portable field spray deposition detection system with simple operation and low price. The purpose of this paper is to develop a direct electrochemical sensor with high sensitivity, good selectivity and stable performance on the basis of electroanalytical chemistry. The hardware processing unit of signal processing circuit, the signal display software processing unit and the key of power supply circuit in the system are designed to realize the construction of the whole system, and the performance analysis experiment of the system is carried out. The main work includes the following aspects: (1) Construction and performance of organophosphorus pesticide electrochemical sensor. Nitrogen-doped graphene nanomaterials were modified on the surface of screen printing electrode to prepare sensitive elements for rapid response to pesticides. A simple and sensitive enzyme-free electrochemical sensor was constructed for the detection of pesticide methyl parathion. The structure of the sensitive part was characterized by scanning electron microscope (SEM). The electrochemical behavior of methyl parathion was studied by using cyclic volt-ampere technique (CV), differential pulse volt-ampere technique (DPV), linear scanning volt-ampere technique (LSV). Because of the unique structure and properties of nitrogen doping, nitrogen-doped graphene has high electrocatalytic activity for methyl parathion in PBS solution. When the signal-to-noise ratio (SNR) is 3, the maximum sensitivity of the sensor to methyl parathion is 15.32 渭 A / 渭 mol. Under the optimized conditions, the sensor has good stability and selectivity. (2) the analysis and design of the key units of signal detection in the system. The hardware unit design of the system conditioning circuit, including potentiostatic circuit design, I V conversion amplifier circuit, filter circuit and power supply circuit design. Under the energy supply of 12V DC power supply, the microampere current signal is converted into an analog voltage signal in the range of 0 鈮，
本文编号：2507789
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