Eco-friendly synthesis of W@Ce2MoO6 surfaces on PEDOT:PSS composites for efficient pesticide monitoring in agricultural produce

Abstract

Fenitrothion (FNT) is a popular organophosphorus insecticide in agriculture, forestry, and public health programs; however, its persistence and toxicity pose serious risks to human health, ecosystems, and non-target organisms, necessitating precise detection and monitoring for environmental safety. We effectively synthesized tungsten-doped cerium molybdate/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(W@Ce<inf>2</inf>MoO<inf>6</inf>/PEDOT:PSS) using an ultrasonication-assisted technique. The content and structure of the synthesized substance were thoroughly investigated utilizing a variety of spectroscopic and analytical methods. The addition of PEDOT:PSS significantly increased the electrochemical conductivity of W@Ce<inf>2</inf>MoO<inf>6</inf>, as shown by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques for electrochemical detection of FNT. The oxidation peak of FNT was measured at +0.42 V vs. Ag/AgCl, and this potential was utilized to create the calibration curve using DPV. The DPV response of FNT at the W@Ce<inf>2</inf>MoO<inf>6</inf>/PEDOT:PSS-modified glassy carbon electrode (GCE) exhibited excellent sensitivity (8.7142 μA μM^₋1 cm⁻²), a broad linear detection range (0.066–136.66 μM), a low limit of detection (LOD) of 6.6 nM, and a limit of quantification (LOQ) of 0.0427 μM. The sensor demonstrated remarkable selectivity in the presence of potentially interfering species, with a percent error of less than ±5 %. Its practical application was proved by identifying FNT in real-world samples such as tomatoes, sweet potatoes, cabbage, apples, oranges, and kiwis. The average recovery rates varied from 97.21 % to 99.86 %, indicating that the sensor is very accurate and reliable for determining FNT in real-world applications.