Pesticide Residues Detection System Development Based On Enzyme Electrode

The food pollution caused by pesticide residues is affecting human life quality, which has become a big concern in China and around the world. Therefore, it is very meaningful to detect the pesticide residues.This paper analyzed the current methods for the detection of pesticide residues and the situation worldwide. Using enzyme electrodes as testing sensors, we have developed a low-cost, high precision pesticide residue detection system. The detection principle of enzyme inhibition method, the architecture of the pesticide residues detection system, hardware design, software and the realization of communication interface design are elaborated in this paper.The system includes constant potential circuits, micro-current detection circuit, controller and its peripheral circuits as well as the communications with the PC. Based on AT89S52 single chip, the detector can convert the faint current signal of the sensor into voltage signal through I/V converter, programable amplifier and filtering. Then the signal of pesticide residues concentration is stored in the EEPROM in the form of digital by a high-accuracy A/D converter. In this system, the current value can be reflected in the form of waveform by communicating the standard RS-232 serial interface with PC.The reliability of the system is improved by a series of anti-jamming measures such as shielding, hardware and software filtering. With the successful development of this system, it will have great potential applications.