Ternary Synergy of UiO‐66, Carboxylated Multi‐Walled Carbon Nanotubes, and Chitosan on Screen‐Printed Carbon Electrodes: A Non‐Enzymatic Electrochemical Platform for Ultrasensitive Methyl Parathion Monitoring in Chinese Herbal Medicines

The excessive use of methyl parathion (MP), a common organophosphorus pesticide in Chinese herbal medicine (CHM) cultivation, has raised significant safety concerns due to hazardous residue levels. To address this issue, we developed a novel non‐enzymatic electrochemical sensor by integrating carboxylated multi‐walled carbon nanotubes (cMWCNTs) with chitosan (CS) and metal‐organic framework UiO‐66. The fabricated UiO‐66@CS@cMWCNTs/screen‐printed carbon electrodes sensor demonstrates exceptional performance in MP detection through a synergistic “adsorption‐catalysis‐amplificatio” mechanism: UiO‐66 provides efficient MP molecule capture, while cMWCNTs facilitate enhanced electron transfer and redox reactions. This sensor achieves an ultra‐low detection limit of 2.33 × 10 −5 μg mL −1 with a wide linear range from 4.0 × 10 −4 to 4.0 × 10 1 μg mL −1 . Practical applications in CHM samples confirm excellent stability and reproducibility, establishing this method as a reliable, high‐sensitivity solution for trace MP detection. The proposed sensor offers significant potential for developing portable devices for on‐site pesticide monitoring in herbal products.