Design And Research Of Portable Organophosphorus Pesticide Residue Detector

Among the commonly used insecticides,organophosphorus pesticides are the most widely used,and can have serious effects on human health and the natural environment.However,there are many problems in the current methods for the detection of organophosphorus pesticides in food and water.The large-scale meteorological such as liquid chromatographs used in the lab are complicated and costly.The existing rapid detection products are not accurate,accessories,operation cumbersome and with other issues.We need to develop rapid,sensitive,portable organophosphorus pesticide testing equipment.In recent years,technology of electrochemical detection combined with biotechnology,microfluidic chip technology and on-chip laboratory technology has become a new direction for the development of chemical detection.This paper introduces the design of portable organophosphorus pesticide detector and pesticide detection chip.According to the functional requirements of the instrument,the paper puts forward the overall design scheme of portable organophosphorus pesticide residue detector.On this basis,the design and manufacture of the detection chip and the hardware and software design of the instrument are completed.In the design and manufacture of the detection chip,the paper discusses the fabrication of the screen electrode,the fabrication of the micro-channel and the immobilization of the enzyme.On the hardware side,this paper discusses the processor control circuit,the constant potential circuit,the weak current detection circuit,the sampling circuit,the design of filter circuit.In software,this paper describes the microprocessor program and Andrew App’s design and development.Finally,precision current source was used to detect the potential of the detector.The electrochemical detection instrument was used to detect the chip.The effect of the organophosphorus pesticide detector was validated.The results show that the potentiostatic circuit can control the potential stability,the error is less than 0.1 mV,the voltage output range of-2.5V to 2.5V.The current limit of microcurrent detection circuit is 0.1 μA,and the detection chip has the resolution of lng/mL for organophosphorus pesticide.The detector can accurately detect pesticide concentration in the range of 1 ng/mL to 1000 ng/mL.