A high-performance non-enzymatic electrochemical hydrazine sensor based on NiCo2S4 porous sphere.

A non-enzymatic electrochemical sensor-NiCo2S4/GCE was constructed for sensitive and selective detection of hydrazine (N2H4), which was designed based on porous nanostructure and synthesized through a facile hydrothermal method. The nanocomposite has been characterized using a series of characterizations such as X-ray powder diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopy (TEM), showing the porous NiCo2S4 sphere was made of interconnected nanoparticles with porous structure. Electrochemical measurements revealed that the porous NiCo2S4 sphere based sensor exhibited an excellent voltammetric response towards the N2H4 oxidation with a wide linear range of 1.7 μM to 7.8 mM, a low detection limit of 0.6 μM (S/N = 3), a sensitivity of 179.1 μA mM-1 cm-2. Moreover, determinations of N2H4 in tap water samples were carried out by standard addition. Acceptable results with relative standard deviation of 2.1-3.0% and recovery of 95.20-103.6% were obtained for five parallel measurements. Therefore, NiCo2S4/GCE promised to be a new platform for electrochemical detection of N2H4.