▎ 摘　　要

The authors describe the synthesis of a nanocomposite consisting of Fe3O4 nanoparticles, polypyrrole and graphene oxide (Fe3O4/PPy/GO), and its application to voltammetric sensing of hydrazine. The nanocomposite can be synthesized by combining chemical oxidative polymerization and co-precipitation. Fe(III) ion is employed as both the oxidant for pyrrole and as a precursor of Fe3O4. The nanocomposite was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). TEM observations revealed that large numbers of Fe3O4 are homogeneously and densely distributed. The Fe3O4/PPy/GO composite was placed in a glassy carbon electrode, and the resulting sensor, best operated at around 0.2 V (vs. SCE) exhibited excellent response to dissolved hydrazine over the 5.0 mu M to 1.3 mM concentration range, a sensitivity of 449.7 mu A mM(-1) cm(-2) and a low detection limit of 1.4 mu M (at an S/N ratio of 3).