Electrochemical preparation of Pt nanoparticles modified nanoporous gold electrode with highly rough surface for efficient determination of hydrazine

A highly sensitive electrochemical sensing platform for hydrazine was developed based on a highly surface-roughened nanoporous gold electrode decorated with Pt nanoparticles (Pt/HNPG). The self-supporting composite electrode is binder-free, which was fabricated via anodization of a commercial AuSn alloy in HCl electrolyte and subsequent electrodeposition of H2PtCl6 precursor in aqueous solution. The morphology and composition of Pt/HNPG electrode were characterized by scanning electron microscopy (SEM), energy dispersive Xray spectrometer (EDS), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of Pt/HNPG towards electrooxidation of hydrazine was examined. It is found that both Pt nanoparticles loadings and solution pH have strong influence on the electrocatalytic activity. At the potential of -0.1 V (vs. SCE), the fabricated composite electrode showed excellent sensing performance for hydrazine with a wide linear range of 5 mu M to 6.105 mM, a low detection limit of 1.03 mu M (signal-to-noise ratio (S/N) of 3) and a high sensitivity of 3449.68 mu A mM(-1) cm(-2). Moreover, the sensor exhibited good selectivity, repeatability and stability. It was also successfully applied for the highly sensitive determination of hydrazine in real water samples with satisfactory results.