In this study, by using a co-precipitation method MoO3/CuO/ZnO nanocomposite material was synthesized. Then the prepared material was fully characterized by using XRD (X-ray diffraction), SEM (scanning electron microscopy), EDS (energy dispersive x-ray spectroscopy), CV (cyclic voltammetry), and EIS (Electrochemical Impedance Spectroscopy). Zeta potential and hydrodynamic size were measured using a Zetasizer in PBS buffer. By using Scherrer's formula from XRD, particle size was determined which was around 26.5 nm. For the promising chemical sensor development, MoO3/CuO/ZnO nanocomposite material was fabricated onto a glassy carbon electrode (GCE) to provide a sensor probe with a fast response towards the selective hydrazine (HZ) toxin in phosphate buffer phase. The fabricated sensor probe is exhibited good sensitivity and long-term stability as well as enhanced electrochemical performances. A calibration plot was found linear in the range of 0.2 nM to 2.0 mM (linear dynamic range, LDR) in presence of aqueous HZ solutions with highest sensitivity value and lower limit of detection and good limit of quantification (LOQ). This approach is promising as an efficient technique in developing a highly effective sensor probe with ternary metal oxides for detecting environmental pollutants on a broad scale.