CuO nanoparticles passivated 2D MXene-based voltammetric sensor for detecting environmental hazardous pollutant

[Display omitted] •The first reported development of a novel MXene-based electrochemical sensor for Diclofenac detection.•Ti3C2Tx MXene/CuO nanocomposite is prepared by a one-pot sonochemical method.•Dimer and Trimer complex-based molecular interaction has been studied by an in-silico semi-empirical (PM6) approach.•The electrochemical sensor successfully establishes a linear range of detection from 0.34 µM to 31.67 µM.•The biosensor developed for the detection of diclofenac in real samples from freshwater pond had a high recovery rate (93.6 % ∼ 111.3 %). This research explores a novel method for electrochemical sensing of the organic pollutant diclofenac sodium. Glassy carbon electrodes (GCEs) were modified with ultrasonically prepared MXene/CuO nanoparticle composites, demonstrating a wide linear detection range of 0.34 µM–31.67 µM for the contaminant. The study involved synthesizing 2D MXene via HF etching and DMSO delamination, and CuO nanoparticles through a hydrothermal process. Powder XRD, FE-SEM, EDAX, HR-TEM, and SAED techniques characterized the synthesized materials and composites. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) were employed to analyze the electrochemical behaviour of the nanocomposites. Furthermore, the binding interaction between the MXene/CuO composite and diclofenac sodium was investigated using molecular modelling and semi-empirical approaches. The results revealed that CuO nanoparticle incorporation significantly enhances the sensitivity of MXene towards diclofenac. This novel sensor exhibited satisfactory performance, suggesting its potential application as a robust platform for environmental monitoring systems.