A novel strategy is developed to synthesize three-dimensional porous Au@Pt core-shell nanoflowers supported on GO (Au@Pt-nFs/GO) for enhanced electrochemical sensing of hydrazine (N2H4). Au@Pt-nFs/GO nanocomposite was synthesized through a facile and green method, where ascorbic acid and chitosan were employed as the reductant and linking agent, respectively. The experiment results revealed that a large numbers of Au@Pt-nFs with Au cores and Pt dendritic shells were distributed on the surface of GO sheets. Meanwhile, Au@Pt-nFs/GO with large surface area, abundant active sites and open structure reduced the overpotential and accelerated kinetics of N2H4 oxidation, therefore making the sensor based on Au@Pt-nFs/GO exhibit an excellent performance for N2H4 analysis with a wide linear range of 0.8 mu M-0.429 mM, a high sensitivity of 1695.3 mu A mM(-1) cm(-2) and a low detection limit of 0.43 mu M (S/N = 3). Moreover, the sensor also exhibited good selectivity, repeatability and stability. Application of the sensor for the detection of N2H4 in tap water samples was demonstrated. (C) 2017 Elsevier B.V. All rights reserved.