CoNi(OH)x/CeO2/MoS2-MWCNTs composite electrode for ultrasensitive detection of methyl parathion in organophosphorus pesticides

The synthesis method of CoNi(OH)x/CeO2/MoS2-MWCNTs/GCE with the method to detect methyl parathion. The study introduces a novel composite electrode, CoNi(OH)x/CeO2/MoS2-MWCNTs, made using a two-step process with ZIF-67. It offers ultrasensitive detection of the pesticide methyl parathion, with high electrocatalytic activity and conductivity for rapid, accurate residue analysis in environmental and agricultural samples. The sensor provides a broad linear response, high sensitivity, and a detection limit of 0.1 nM, surpassing other methods. Validated with real samples, it shows accuracy and reliability with 98.4–108% recovery rates, enhancing the application of nanocomposites in electrochemical sensing. [Display omitted] •An electrochemical CoNi(OH)x/CeO2/MoS2-MWCNTs/GCE sensor is presented for methyl parathion determination.•High selectivity, repeatability and reproducibility of the sensor are obtained.•Good linear concentration ranges of 1.0 to 10.0 µM with low LOD (0.1 nM) are observed.•The developed sensor could be applied in methyl parathion detection in actual samples. This research presents the development of a novel composite electrode material, CoNi(OH)x/CeO2/MoS2-MWCNTs, synthesised via a two steps reflux process with ZIF-67 as precursor for the ultrasensitive detection of methyl parathion, a widely used organophosphorus pesticide. This electrode material demonstrates superior electrocatalytic activity and conductivity, enabling the rapid and accurate detection of methyl parathion residues in environmental and agricultural samples. The study extensively characterises the synthesised material using SEM, XRD, EDS, and EIS, confirming its unique nanostructure and elemental composition. The sensor exhibits a wide linear response range, high sensitivity, and a low detection limit of 0.1 nM, outperforming many existing methods. The practical application of the sensor is validated through objective sample analysis, showing high accuracy and reliability with recoveries between 98.4 % and 108 %. This work introduces a highly efficient sensor for methyl parathion detection and contributes to the broader application of nanocomposite materials in electrochemical sensing.