有机磷农药残留光化学传感器设计与实现

Design and Implementation of Organophosphorus Pesticide Photochemical Sensor

为了快速检测农产品中有机磷农药残留,本文设计了一种基于酶抑制与光谱吸收的农药残留现场检测的光化学传感器。该传感器主要包括光学激发模块、信号处理模块及传感器软件等三部分。此外,传感器还集成了干式恒温系统,控制检测过程中的溶液温度。通过研究了酶促反应的吸光度变化与时间的关系、温度与酶活性的影响,建议选择酶促反应前3mm至5 min内吸光度变化值来计算抑制率,反应选在37℃下进行。传感器对敌敌畏、对硫磷、甲胺磷、乐果的检出限分别为0.015,0.2,0.4,0.5 mg/L,具有较低的检出限。同时,传感器重复性较好,对同一样品的抑制率检测标准偏差仅为0.5293。此外,在实际样品的检测中,传感器检测结果与实验分析方法 -分光光度法与气相色谱法的相关性较好,差异小且无假性结果,进一步证明了传感器检测结果的准确可靠。

In this paper,a photochemical sensor based on enzyme inhibition and spectral absorption is designed for the rapid detection of organophosphorus pesticide in agricultural products. It mainly includes optical excitation module,signal processing module and detection software. Additionally,the sensor also integrates the temperature control system to keep the temperature in the process of detection. In consideration of relationship between time of enzymatic and absorbance changes and the effects of temperature on the enzyme activity,the absorbance changes within 3 ~ 5min enzymatic reaction is suggested to calculate the inhibition rate,and the appropriate reaction should choosen be at37 ℃. The detection limit of dichlorvos,parathion,methamidophos,dimethoate are 0. 015,0. 2,0. 4,0. 5 mg / L,so the sensor has low detection limit. And the sensor has good repeatability for the same sample standard deviation of the inhibition rate is only 0. 5293. Moreover,the detection results of the sensor,spectrophotometer and gas chromatograph are in good correlation and of the small differences in the actual sample detection. The further detection of the sensor is accurate and reliable.