Effect of Hydrazine Hydrate on Reduced Graphene Oxide for Enhanced Electrochemical Sensing of Pb(II)

This study examines the effect of hydrazine hydrate levels on chemically reduced graphene oxide (GO) to synthesize reduced graphene oxide (rGO) for Pb (II) electrochemical detection. GO was prepared by the modified Hummers’ method and reduced with 1-5 mL hydrazine hydrate. FTIR analyzed changes in oxygen-containing groups. rGO samples were drop-cast onto screen-printed carbon electrodes (SPCEs) and characterized by SEM-EDX. Electrochemical behavior was evaluated by cyclic voltammetry (CV) in 5 mM [Fe (CN)₆]³⁻/⁴⁻ with 0.1 M KCl. rGO reduced with 3 mL hydrazine hydrate showed the highest current (52.45 ± 1.98 µA), a 196.6% increase over bare electrodes. This condition also gave the best detection of 1 ppm Pb (II) in 0.1 M acetate buffer (pH 5) via square wave anodic stripping voltammetry (SWASV), with a 135.0% signal enhancement. These results highlight the importance of hydrazine hydrate level on optimizing rGO for improved electrochemical properties, sensitivity, and reproducibility for Pb (II) detection.