However the usage of insecticides are essential to safeguard the crops, the increase in its permissible levels imposes several health issues. The organophosphate insecticides like fenitrothion (FNT) are known for its rapid migration properties and adverse health effects. Therefore, precisely detecting the dissemination of FNT in ecology is very much essential. In this article, we reported a synthetic approach to rGO-Tungsten carbide nano polyhedrons (rGO-WC NPHs) composite. Then economically, rGO-WC NPHs were fabricated on the screen printed carbon electrode (SPCE) for the determination of FNT in environmental water and forest soil samples. As expected its shows moral analytical parameters, such as wider linear range of 10 nM-471.2 mu M, with the very low detection limit of 1.15 nM. The sensitivity possessed by the prepared robust FNT detector is 5.3760 mu A mu M(-1)cm(-2). The results acquired for the developed sensor (rGO-WC NPHs/SPCE) were also compared with the standardized HPLC method to validate the robustness of the sensor.