A Miniaturized Portable Instrument for Rapid Determination Pesticides Residues in Vegetables and Fruits

In this paper, we developed a portable pesticides residues detection instrument by integrating an amperometric acetylcholinesterase (AChE) biosensor and a signal detecting circuit. The AChE biosensor was modified with tin oxide (SnO₂) nanoparticles, chitosan, and multiwalled carbon nanotubes nanocomposite. Because the signal generated from the acetylcholinesterase biosensor is very weak, an analog signal detect circuit is elaborately designed to reduce lots of the noises and system drifts. This instrument could realize rapid detection of pesticides residues in fruits and vegetables on-site with automatic data processing, display, and data storage. The detection limit was 100 ng/L. The measurement time from sample treatment to detection was 15 min. Compared with traditional analytical methods, this proposed pesticides residues detection instrument possessed a good precision and high stability. This will be a new promising rapid detection instrument for pesticides residues in agricultural products.