Research On Rapid Detection Device For Pesticide Residues Based On Liquid Sensing Array

According to statistics,China is a large country of pesticide production and consumption in the world.Environmental pollution and food safety problems caused by pesticide residues are not optimistic and pose a serious threat to human health.Among the existing pesticide residue detection methods,the instrumental analysis method represented by chromatography is not suitable for rapid on-site detection due to the large equipment and complicated detection process;Some screening methods that can be used for rapid detection in the field,such as the enzyme sensor method,need to be improved in accuracy;The spectroscopy method is based on the advantages of high sensitivity,fast detection speed and easy integration into portable devices,The spectroscopy method is based on the advantages of high sensitivity,fast detection speed and easy integration into portable devices,which can meet the requirements of systemic,miniaturized and real-time detection of pesticide residue detection products on the market.This paper aims to develop a new pesticide residue detection device based on the spectrophotometric detection principle of spectrophotometry,according to the existing research foundation of the research group on cross-response array,and the advantages of microfluidic chip such as high flux and miniaturization.In this paper,based on the principle that the sensitive points of the cross response array on the microfluidic chip are different from the absorbance changes before and after the action of different pesticides,a set of pesticide residue detection device is designed,which provides a basis for the research and development of portable pesticide residue detection instrument based on the liquid cross response array.The research content of this paper mainly includes the following aspects:(1)Based on the theoretical study of absorbance method,combined with the principle of cross response array and microfluidic chip technology,through the analysis of the system function,the overall design scheme of the device was proposed,and the research work was divided into three parts: centrifugal microfluidic chip design,the design of each part of the detection device,and the design of hardware and control software of lower computer.(2)Based on the advantages of microfluidic chip,centrifugal microfluidic chip is adopted as the reaction carrier of the cross response array.Based on the inertial motion trajectory of the droplet on the disk subjected to centrifugal force,the Solidworks software is used to design the structure and size of the chip,and the fluent software was used to model and simulate the chip flow passage.Then,based on the structure of microfluidic chip and the installation method of electronic components,using Solisworks software to design and simulate other components of the device.Finally,the 3D printing technology is used to finish the machining of each design part.(3)According to the functional requirements of the detection device based on the absorbance spectrophotometry for the control circuit of the lower computer,the Autilm Designer was used to complete the schematic design of the hardware circuit of the lower computer.It mainly includes microcontroller module,light source driver module,spindle motor driver module,signal processing module,power supply module and serial communication module.Then,the software design of the spindle motor drive module and serial port communication module is completed under the keil development environment.(4)System debugging and verification.Independently debug and test each component,hardware function module and software control module of the device.The detect device was used to test the 4 pesticide solutions,and the pattern recognition of the detection data was carried out through the data analysis software.The analysis of the test results showed that the device could be used to detect and distinguish different kinds of pesticide solutions.