▎ 摘　　要

A simple, low cost, and highly sensitivity chemical sensor development with various nanocomposites (NCs) of Mn3O4-CNT and compared the performances fabricated with Mn3O4, Mn3O4-CB (carbon black), Mn3O4-GO (graphene oxide) prepared by simple wet-chemical approach in alkaline media (pH > 10). The nanocomposites were characterized by various methods, such as UV/vis. spectroscopy, transmission electron microscopy (TEM), X-ray diffraction pattern (XRD), FT-IR, and X-ray photoelectron spectroscopy (XPS) etc. The NCs were embedded on a flat glassy carbon electrode (GCE; Surface area: 0.0316 cm(2)) using binders (nafion with 5% ethanolic solution) to produce a selective hydrazine sensor. The fabricated GCE with Mn3O4-CNT NCs was used as chemical sensor successfully to detect selective hydrazine chemical in phosphate buffer solution (PBS) within short response time via simple and reliable electrochemical method. The fabricated Mn3O4-CNT NCs chemical sensor showed higher sensitivity (1100.0 mu A mu M(-1)cm(-2)) with a very low limit of detection (LOD) of 0.86 nM (signal-to-noise ratio at an SNR of 3). The calibration curve plot is linear in large concentration range of hydrazine (LDR) from 2.0 nM to 2.0 mM. At the end, it can be assumed that this selective chemical sensor has numerous advantages such as ease of integration, higher stability, reliability, reproducibility, lower limit of detection, and higher selectivity for the chemicals of toxic hydrazine for the environment's safety.