An insect acetylcholinesterase biosensor utilizing WO3/g-C3N4 nanocomposite modified pencil graphite electrode for phosmet detection in stored grains

Abstract

This study was undertaken to assess the potential of Tribolium castaneum (Red flour beetle) acetylcholinesterase (Tc-AChE) based electrochemical biosensor integrating WO₃/g-C₃N₄ nanocomposite modified Pencil graphite electrode to detect an organophosphate insecticide, Phosmet. The WO₃/g-C₃N₄ nanocomposite provides a non-toxic, biocompatible surface for binding the enzyme on the electrode surface, attributed to its large surface area, high conductivity, and low ohmic resistance. The proposed biosensor shows a very good analytical performance with LOD 3.6 nM for Phosmet and effectively determined Phosmet in wheat with a 99% recovery rate. Furthermore, molecular docking deciphers the binding interactions of Phosmet with Tc-AChE using a modified AutoDock LGA algorithm and an AMBER03 force field in YASARA. The kinetic parameters strongly suggest the high potency of inhibitor with the enzyme. This study presents an adaptable, rapid, and straightforward approach that opens ways towards real progress in developing commercial biosensors for pesticide detection.

Keywords: Acetylcholinesterase; Acetylthiocholine chloride (PubChem CID22411); Docking; EDC (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide) (PubChem CID2723939); Graphitic carbon nitride; MES (4-morpholinoethanesulfonic acid) (PubChem CID78165); Melamine (C(3)H(6)N(6)) (PubChem CID7955); NHS (N-hydroxysuccinimide) (PubChem CID80170); Pencil graphite electrode (PGE); Phosmet; Phosmet (PubChem CID12901); Potassium ferricyanide (K(3)[Fe(CN)(6)]) (PubChem CID26250); Potassium ferrocyanide (K(4)[Fe(CN)(6)]) (PubChem CID11963580); Tribolium castaneum (Red flour beetle); Tungsten oxide.