A novel hybrid nanocomposite based on de-layered molybdenum disulfide (MoS2) by ionic-liquid (IL, [BMIM]BF4)-assisted exfoliation and graphene oxide (GO) was synthesized via a green, efficient, and high-quality method, which combined liquid-phase stripping method and ion-insertion method. In addition, an electrochemical sensor was developed using the MoS2-IL/GO nanocomposites for the determination of chloramphenicol (CAP). The morphology and structure of these synthetic materials were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray diffraction and the electrochemical characterization by cyclic voltammetry and electrochemical impedance spectroscopy. Based on this method, the insertion of IL can effectively exfoliate de-layered MoS2, and the MoS2-IL/GO nanocomposite exhibit 3D structure with higher surface area, excellent electrical conductivity, and synergistic catalytic capabilities. Under optimized conditions, the sensor responded linearly to CAP ranging from 0.1 to 400 mu mol L-1 and the detection limit of 0.047 mu mol L-1. In addition, the sensor showed excellent stability, repeatability, reproducibility, and selectivity, and has been applied to detect CAP in eyedrops, milk, and urine samples. [GRAPHICS] .