An impedimetric biosensor based on poly(l‑lysine)‑decorated multiwall carbon nanotubes for the determination of diazinon in water and fruits

Ali R. Zare, Ali A. Ensafi, B. Rezae, ournal of the Iranian Chemical Society volume 16, pages 2777–2785 (2019)

https://link.springer.com/article/10.1007/s13738-019-01741-z

Abstract A new electrochemical biosensor is developed for the detection of diazinon. For this purpose, a glassy carbon electrode is modifed with MWCNTs and poly-l-lysine to immobilize a double-strain DNA (ds-DNA) on the surface of the electrode. In the frst step, the interaction of diazinon with ds-DNA is transduced by electrochemical impedance spectroscopy and UV–Vis spectroscopy to monitor the intercalation of diazinon with DNA helix. This interaction leads to reduced interfacial charge-transfer resistance (Rct). The diference in the Rct before and after the interaction is considered as a suitable signal for diazinon detection. The proposed biosensor has a low detection limit (0.3 nmol L−1), a wide linear dynamic range (0.001‒100 µmol L−1), and high selectivity for the determination of diazinon. Finally, the performance of the biosensor for detecting of diazinon is verifed in real samples such as river water, agricultural wastewater, lettuce juice, and tomato juice.

Keywords Electrochemical biosensor · MWCNTs · Poly(l-lysine) · DNA · Diazinon detection