We recently reported in this journal the preparation and characterization of a nanostructured AuCu3 alloy electrode for use as chemical sensors. This alloy electrode was prepared from a barrel-plated gold electrode (AuBPE) consisting of copper main body with successive plating of nickel and gold by manipulating the grain boundary diffusion through thermal annealing treatment and electrochemical activation in alkaline solution. In this study, based on a more detailed XRD study, we tend to explain how the nanostructured film is attained for this AuCu3 alloy electrode. The structural characterization and electrochemical behavior of the AuCu3 alloy were performed by XRD, EDS, and cyclic voltammetry. We further demonstrated its application as an electrochemical sensor towards non-enzymatic detection of hydrazine with good selectivity. Compared to that of AuBPE, the sensitivity for hydrazine detection using cyclic voltaminetry was found to increase by similar to 24.8 times with a low peak potential of similar to 0.0 V vs. Ag/AgCl in neutral medium. Flow injection analysis of hydrazine shows a wide linear calibration range of 0.1 mu M to 1 mM and further increases the sensitivity with a detection limit down to 0.04 mu M (S/N = 3). Real sample analysis was successfully demonstrated for the detection of hydrazine in environmental water samples. (C) 2013 Elsevier Ltd. All rights reserved.