In recent years, development of efficient green nano technology is generating interest of researchers toward ecofriendly bio-synthesis of nano particles. In the present study, we report the bio synthesis of aqueous stable gold, silver, palladium, and other nanoparticles by using Green Tea and Coffee leaf extract as both reducing and capping agents. The Green Tea and Coffee leaf extract reduced gold, silver, palladium and form nanoparticles. Nanoparticles were characterized by UV/Vis, particle size analyzer (PSA) and transmission electron microscopy (TEM). Additionally, AuNps, AgNps, PdNps etc. have been investigated for Poly phenols and Caffeine in "GREEN SYNTHESIS OF TEA AND COFFEE EXTRACT". We discuss here a quick, simple, economic, and ecofriendly method through a completely green route for the selective detection. The method has been successfully applied for determination of Poly phenols and Caffeine in Tea and Coffee leaf extracts. Thus, this method can be used for rapid andeco-friendly bio synthesis of stable AgNps, AuNps, and PdNps.Further more this Nanoparticles have applied in biological system like, gold Nanoparticles for selective sensing of amino acid(Tryptophan) and