A new electrochemical sensor based on nanostructured carbon paste electrodes (CPEs) is developed for the sensitive detection of Isoproturon in water. The CPEs were nanostructured by incorporation of carbon nanotubes (NTCs) and synthetized copper oxide nanoparticles (CuO). They were characterized using the X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and voltammetric methods. Electrochemical experiments showed that the adsorption of Isoproturon on to (GC-NTC-CuO)-CPE, associated with nanomaterials (NTCs and CuO), provided remarkable analytical performances of the sensor such as a large quantification range from 1 to 200 mu g L-1 with a detection limit of 0.1 mu g L-1 of Isoproturon and no interferences of some another pesticides tested (specificity of ISO adsorption in acidified water). The tests carried out on real samples of water are conclusive. The analytical performances of the sensor showed that it is suitable for the specific determination of pesticide traces in water.