Electrochemical Investigation and Voltammetric Determination of Hydrazine Based on Organic Modifier and N-Doped Reduced Graphene Aerogel/ Molybdenum Oxide Nanorods Multilayer Nanocomposite Modified Glassy Carbon Electrode

In this research, a novel modified glassy carbon electrode (GCE) was successfully fabricated with a tri-component nanocomposite consisting of 5-(3,4-dihydroxyphenyl)8,8-dimethyl-2-(methyl thio)-7,8,9,10-tetrahydropyrimido [4,5-b]quinolone-4,6(3H,5H)-dione (PQ23) and Nitrogen-doped reduced graphene oxide aerogel/molybdenum oxide nanorods (PQ23/N-doped-rGO/MoO2 /GCE) as sensing platform toward hydrazine (HDZ). The nanocomposite is characterized by MAP analysis, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Through electrochemical investigations, the electron transfer coefficient between PQ23 and the N-doped-rGO/MoO2 /GCE (glassy carbon electrode which was modified with reduce graphene oxide decorated by molybdenum oxide nanorods) and the apparent charge transfer rate constant, ks, and diffusion coefficient (D) were calculated. Electrochemical behavior and electrocatalytic activity of the nanocomposite modified GCE were studied by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). Under the optimum experimental condition, the designed sensor exhibited high sensitivity and suitable selectivity for hydrazine oxidation, enabling the detection of hydrazine with a linear range of 25.0-1000.0 µM and a good detection limit (3σ) was 4.2 µM. The designed electrochemical sensor shows good repeatability, reproducibility, and acceptable stability with an RSD less than 3.2%.