Fabrication of phenazopyridine sensor based on electrodeposition of Pt nanoparticles on H-CaFe-Cl-layered double hydroxide film modified glassy carbon electrode

A sensitive phenazopyridine sensor has been developed by electrodeposition of Pt nanoparticles on H-CaFe-Cl-layered double hydroxide modified glassy carbon. Electrochemical impedance spectroscopy and cyclic voltammetry were used to investigate the formation of H-CaFe-Cl-layered double hydroxide film and Pt nanoparticles on the electrode surface. The properties of modified electrode were characterized by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The fabricated sensor exhibits outstanding electrocatalytic activities toward the oxidation of phenazopyridine. The oxidation peak current was proportional to the concentration of phenazopyridine from 5 × 10− 8 to 6.9 × 10− 4 mol L− 1 including two linear segments with a detection limit of 6.3 × 10− 9 mol L− 1 at signal to noise ratio of 3. The proposed method was examined as a selective, simple and precise method for voltammetric determination of phenazopyridine in real samples with satisfactory results.