Fabrication of a sensitive electrochemical sensor of 2,4-dichlorophenoxyacetic acid herbicide based on synergistic catalysis of silver/manganese oxide nanoparticles and polyalizarin at low potential

A new electrochemical method for determining 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solutions was proposed. A glassy carbon electrode was modified with silver, manganese oxide nanoparticles, and alizarin yellow R polymer (Ag-MnOxNPs/PAYR). Scanning electron microscopy, energy dispersive X-ray spectroscopy and electrochemical impedance spectroscopy were used in order to characterize the modified electrode. The electrochemical attributes of 2,4-D at pH 1–13 were studied with the proposed electrode. In order to investigate the electrocatalytical oxidation attributes of this sensor, cyclic voltammetry and differential pulse voltammetry (DPV) were used. The linear range (22–11,752 μM) and detection of limit (7.33 μM) were appraised for oxidation peak at 0.8V by cyclic voltammetry method. In addition, the linear range (6–14,308 μM) and detection of limit (2 μM) were obtained by DPV technique. Results illustrated that the modified electrode has low detection limit, high linear range, and good repeatability at pH 6. Furthermore, this electrode was used for the analysis of 2,4-D in water samples.