The magnetite/reduced graphene oxide (Fe3O4/RGO) composite was synthesized by a facile one-pot in-situ method and characterized by transmission electron microscopy, atomic force microscopy, vibrating sample magnetometer, X-ray powder diffraction, surface area and pore size distribution, thermogravimetric analysis, Raman spectroscopy and X-ray photoelectron spectroscopy, respectively. The composite consisted of the RGO substrate with a single-layered Fe3O4 nanoparticle film, which showed the large surface area of 352 m(2) g(-1) and the saturated magnetization of 26.7 emu g(-1). The average diameter and coverage ratio of Fe3O4 were about 8 nm and 50%, respectively. The electrocatalytic oxidation and detection of N-acetylcysteine (NAC) based on composite-modified glassy carbon electrodes (GCE) were investigated by cyclic voltammetry, amperometry, double potential step chronoamperometry and differential pulse voltammetry. Especially, the kinetic performance of oxidation processes were estimated by the Cottrell equation, indicating the diffusion coefficient of 2.06 x 10(-5) cm(2) s(-1) and the catalytic reaction rate constant of 3.47 x 10(6) cm(3) mol(-1) s(-1). Compared with the kinetic parameters, it was found that the oxidation process included both slow absorption and quick diffusion processes. The detection limit of NAC was 1.11 x 10(-5) mol L-1 in the range of 0.10-10.0 mmol L-1. (C) 2013 Elsevier Ltd. All rights reserved.