Carbon black supported Au–Pd core-shell nanoparticles within a dihexadecylphosphate film for the development of hydrazine electrochemical sensor

[Display omitted] •Au–Pd core–shell nanoparticles supported on carbon black were synthetized.•The core–shell structures were confirmed by TEM and EDS.•Hydrazine was determined by amperometry with the core–shell modified electrode.•The new method was used in the determination of hydrazine in water samples. An amperometric method for the determination of hydrazine (HDZ) using a glassy carbon (GC) electrode modified with carbon black supported Au–Pd core–shell structured nanoparticles (Au@Pd/CB) within dihexadecylphosphate (DHP) film (Au@Pd/CB-DHP/GCE) is proposed. Au@Pd nanoparticles were synthesized by chemical reduction of AuCl3 and PdCl2 using ethylene glycol as a reducing agent, and the nanoparticles supported on CB were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. The proposed Au@Pd/CB-DHP/GCE and CB-DHP/GCE (without Au@Pd) electrodes were used to investigate the electrochemical behavior of HDZ using cyclic voltammetry. When the Au@Pd/CB-DHP/GCE was used, an electrocatalytic effect was observed, the analytical signal was substantially increased (87%) and the oxidation potential decreased, i.e. in 728mV. Additionally, the apparently heterogeneous electron-transfer rate constant (k0) obtained for the Au@Pd/CB-DHP/GCE (0.15cms−1) was about two orders of magnitude greater than that obtained using the CB-DHP/GCE (0.068cms−1). Under the optimized conditions for the amperometric technique, a linear analytical curve for HDZ was obtained in the range of 2.50–88.0μmolL−1, with a limit of detection of 0.23μmolL−1 (0.0074ppm). The proposed method was satisfactorily applied to determine the concentration of HDZ in natural lake and tap water samples.