便携式农药残留检测仪的设计

Design of portable pesticide residue measuring instrument

介绍一种基于酶电极生物传感器的便携式农药残留检测系统,该系统采用STC12C5A60S2微处理器作为控制核心,应用电流型酶电极生物传感器作为检测部件对果蔬提取液进行电化学分析。酶电极产生的μA级微弱电流信号通过I/V变换、差分放大、低通滤波等电路调理后送给A/D转换器,经微处理器运算、量化后将被测液农药残留浓度进行液晶显示并通过微型打印机打印出测试结果。该系统采用RS232总线进行数据上传,上位机应用界面采用LABVIEW编写,可对样本检测结果进行存储、分析、历史数据查询等操作。通过大量果蔬验证性试验,证明该系统稳定可靠、精度高、效果良好。

A portable pesticide residue detection system based on enzyme electrode biosensor was introduced. With microprocessor STC12C5A60S2 as the control center, current electrode enzyme biosensor as testing components, the electrochemical analysis on fruit and vegetable extract was made. The μA level weak current signal produced by enzyme electrode was sent to A/D converter after the circuit adjusting such as： I/V transformation, differential amplifier, low- pass filtering, and then it was calculated and quantified by microprocessor. The density of pesticide residue was displayed on liquid crystal screen and printed out by miniprinter. With host computer application interface written by LABVIEW, using RS232 bus to upload data, this system can store and analyze sample test results and inquire historical data. Through a lot of confirmatory experiments on fruit and vegetable, it is proved that the system is stable and reliable with high precision and good effect.