A new palladium nanoparticles immobilized organic-inorganic hybrid nanocomposite material is prepared to combine the mechanical strength offered by the inorganic matrix with flexible binding sites provided by the organic polymer. The organic polymer is based on a natural polysaccharide, gaur gum grafted with poly(acrylamide) and the inorganic matrix is based on silica. The nanocomposite is characterized by physico-chemical methods, surface characterization techniques and electrochemical methods. This material is coated on a glassy carbon electrode and utilized for electrocatalytic oxidation of hydrazine (HZ). Electrocatalytically HZ is oxidized at lowest overpotential (-0.15 V vs. SCE) than ever reported. Based on the linear increase in catalytic current, a sensitive HZ amperometric sensor is constructed. The sensor displays two linear calibration ranges from 50.0 mu M to 0.6 mM and from 0.6 mM to 180 mM for HZ with high stability and reproducibility. Limit of detection is found to be 4.1 mu M with high sensitivity and selectivity. These properties make the nanocomposite film a promising electrochemical sensing platform for the determination of HZ. Chronoamperometry and cyclic voltammetry studies are used to evaluate kinetic parameters. (C) 2014 Elsevier Ltd. All rights reserved.