Non-enzymatic electrochemical detection of methyl parathion using a UiO-66@MWCNTs/AuNPs/ABSA composite and application to traditional Chinese herbs

A sensor based on UiO-66@MWCNTs, AuNPs, and ABSA was constructed for methyl parathion detection. • UiO-66@MWCNTs provides abundant Zr OH sites for MP adsorption and preconcentration. • The sensor exhibits a wide linear range (0.1–15 μg·mL −1 ). • Satisfactory recoveries (97.43%–101.5%) were obtained in traditional Chinese herbs. A non-enzymatic electrochemical sensor for methyl parathion (MP) was developed based on UiO-66@MWCNTs/AuNPs/ABSA composites. These composites were synthesized via a solvothermal route, followed by AuNPs electrodeposition and ABSA electropolymerization. The UiO-66@MWCNTs matrix offers a large surface area and abundant binding sites for organophosphorus groups, enhancing MP adsorption and preconcentration. AuNPs effectively boost conductivity and catalytic activity, while the electropolymerized ABSA further facilitates electron transfer due to its excellent electrocatalytic properties. Thus, the composite displays remarkable electrocatalytic activity toward MP. Using the MP reduction peak current, the sensor achieves a linear range of 0.1–15 μg·mL −1 and a detection limit of 0.0152 μg·mL −1 (S/N = 3). It also exhibits good selectivity, satisfactory reproducibility (RSD 1.93%), excellent repeatability (RSD 1.50%), long-term stability (99.96% retention after 15 days), and successful application in traditional Chinese herbs such as Coptis chinensis French. and Citri Reticulatae Pericarpium .