Nanotechnology based devices are widely explored in the field of electronics, communication, bio-medical, sensing etc. In addition to these, the potential of nanotechnology baseddevices is very large in the field of agriculture with respect to addressing global challenges of various levels of pollutions, environmental monitoring, food quality analysis, enviornmental decontimantion, climate change, water purification, plant protection, pesticide detection etc. This has accelerated a lot of research in the development of variety of nanomaterials and nanotechnology-derived devices owing to ease of portability, better stability, and sensitivity.Nanocrystalline Gold in the form of quantum dots, nanocapsules, thin films and nanoparticles are already in use for the detection of pesticides, the enhancement of nutrients absorption by plants, the delivery of active ingredients to specific sites and water treatment processes. In current Study Gold Nanoparticles (GNPs) prepared by chemical route of ~8 nm in diameter were used for the detection of organochlorine endosulfan pesticide (ESP) as Colormetric Sensor and the design of GNPS based chemical sensor for its quantitative estimation has also been proposed. The Original wine red color of GNPs changes in to various shades of blue after addition of different concentrations of ESP solutions. This change in solution colour is attributed to the decrease in inter-particle distances to less than approximately the average particle diameter due to re-organization of GNPs into aggregates in the form of patterned and non-patterned structures. These results are also confirmed by UV-VIS spectroscopy, in which surface plasmon resonance and its second order peaks are observed in their visible spectra. GNPs based sensing electrode has been used for designing of ESP detection chemical sensor at ambient temperature. The response and sensitivity of ESP sensor parameters are obtained from their recovery curves between the change in resistance vs. time. The result shows minor variation in resistance with ESP concentration with good repeatability. The results will be discussed in detail at the time of presentation.