In this chapter, the role of noble metals and their contribution in synthesis of Nano sensor has been discussed, that can be used to detect environment and its quality. These nanosensors, which are used to monitor the quality of water, have versatile properties for detecting organic pollutants with great sensitivity and selectivity as well as heavy metals. These nanosensors are best in detecting and quantifying particulate matter and other air contaminants, theses sensor also integrated into sensor network for ecosystem mentoring. The roles of gold, silver, copper, and platinum nanoparticles is studied. platinum nanoparticles are highly valued due to their unique properties that detect the precise and accurate measurement of environmental contaminants, making them best for environmental monitoring. Noble metal nanoparticles can be used to enhance the accuracy, precision and efficiency of environmental, detection to ensure public health by optimization of these nanoparticles and syntheses of efficient nanosensor based on these nanoparticles can be very efficient for the healthy environment and ecosystem. Using these advancements, we can make a sustainable green environment with improved health and ecosystem for all type of living organism.