Organophosphorous pesticides detection system based on amperometric enzyme biosensor

In this paper, a pesticide detection system is designed based on amperometric acetylcholinesterase biosensor for rapid detecting pesticide residues in fruits and vegetables. This system made use of the electrochemical characteristic of enzyme catalyzing substrate of acetylcholinesterase biosensor for detecting pesticide residues. The behavior of cyclic voltammograms (CV) of the prepared biosensor is studied and based on this CV characteristic the data acquisition and processing circuit of the weak current signals generated by the biosensor is designed, which including the I/V conversion, differential amplification, low-pass filter, A/D conversion etc. Eventually, the 0∼5V voltage signal are obtained and they are proportional to the weak current from the enzyme biosensor. Four kinds of standard pesticide of different concentrations was tested with the detection system respectively, the results showed that the detection limits are all lower than 5µg/kg.