Ultrasensitive non-enzymatic electrochemical detection of paraoxon-ethyl in fruit samples using 2D Ti3C2Tx/MWCNT-OH

Abstract

This study reports on the development of a highly sensitive non-enzymatic electrochemical sensor based on a two-dimensional Ti₃C₂T_x/MWCNT-OH nanocomposite for the detection of paraoxon-based pesticide. The synergistic effect between the Ti₃C₂T_x nanosheet and the functionalized multi-walled carbon nanotubes enhanced the sensor's conductivity and catalytic activity. The nanocomposite demonstrates superior electrochemical and electroanalytical performance compared to the pristine Ti₃C₂T_x and MWCNT-OH in detecting paraoxon-ethyl in fruit samples (green and red grapes), with a linear response range from 0.1 to 100 μM, a low limit of detection (LOD) of 10 nM, limit of quantitation (LOQ) of 70 nM, and sensitivity of 0.957 µA μM⁻¹ cm⁻² at pH 8. Furthermore, the sensors maintain excellent selectivity and effectiveness in detecting paraoxon-ethyl even in the presence of various interferents, including diazinon, carbaryl, Fe²⁺, NO₂⁻, NO₃⁻, ascorbic acid, and glucose. The facile fabrication and enhanced sensing capabilities of the Ti₃C₂T_x/MWCNT-OH nanocomposite position it as a reliable, cost-effective, and sustainable alternative to conventional detection systems for monitoring pesticide residues in agricultural products.