A novel electrochemical sensor was developed by electrodepositing gold nanoparticles on the single walled carbon nanohorns modified glassy carbon electrode. We used the prepared sensor to determine hydrazine for the first time. The results show that the modified electrode has good electrocatalytic activity toward the oxidation of hydrazine. Under the optimized conditions, two wide linear segments were observed between the catalytic currents and the concentration of hydrazine within the range of 0.005-3.345 mM with a detection limit of 1.1 mu M (s/n = 3). The diffusion coefficient of hydrazine was also estimated using chronoamperometry. Additionally, the sensor showed excellent sensitivity, selectivity, and reproducibility properties. (C) 2016 Elsevier B.V. All rights reserved.