Poly(sodium 4-styrenesulfonate) (PSS) intercalated graphene (PSS-GN) was prepared via in situ reduction of exfoliated graphite oxides in the presence of PSS, and then mixed with CTAB to form a stable PSS-GN-CTAB nanocomposite through electrostatic self-assembly. The prepared composites were characterized by Fourier transform infrared spectrometry (FT-IR), ultraviolet and visible spectrometry (UV-vis) and Xray diffraction (XRD). A novel 2,4-dichlorophenol (2,4-DCP) electrochemical sensor was fabricated based on a PSS-GN-CTAB modified glassy carbon electrode. It was found that the composite of PSS-GN-CTAB exhibited excellent electrocatalytic activity towards the oxidation of 2,4-DCP. Linear sweep voltammetry (LSV) was used for the quantitative determination of 2,4-DCP. Under the optimum conditions, the peak current of 2,4-DCP was proportional to its concentration at the range of 1.0 X 10(-8) to 2.0 x 10(-6) mol L-1 with a detection limit 2.0 x 10(-9) mol L-1. The newly developed method was successfully applied for the determination of 2,4-DCP in the waste water with good recoveries. The proposed electrode system represents a new platform for designing excellent electrochemical sensors with water-dispersed graphene. (C) 2014 Elsevier Ltd. All rights reserved.