Rapid Detection Technology for Pesticides Residues Based on Microelectrodes Impedance Immunosensor

Abstract

Compared with conventional methods, electrochemical immunosensors have many advantages, such as low cost, high sensitivity, and rapid detection, and has certain prospects for realizing real-time-monitoring. In this paper, a design of portable pesticide residues detection instrument was presented based on an electrochemical impedance immunosensor. Firstly, we studied on an impedance immunosensor based on interdigitated array microelectrode (IDAM) coupled with magnetic nanobeads-antibody conjugates (MNAC) for the pesticide detection. Magnetic nanobeads (diameter 150 nm) coated with anti-carbofuran antibodies were used for further amplification of the binding reaction between antibody and hapten (carbofuran). Secondly, in order to develop a portable pesticide residue apparatus, we designed the impedance detection electric circuit. Main work included designing and constructing of the system circuit, designing and debugging of the system software and so on. Thirdly, the apparatus was used for the standard pesticides solutions testing combined with immunosensor to test the reliability and stability. The pesticide added standard recovery was more than 70 % and the impedance test error was less than 5 %. The results showed that the proposed instrument had a good consistence compared with the traditional analytical methods. Thus, it would be a promising rapid detection instrument for pesticide residues in agricultural products.

Keywords

• Pesticide residues
• Immunosensor
• Interdigitated array microelectrode
• Signal detection
• Portable instrument.