Progressing in time proved development in technology that showed the ability of metals of nanoscale to perform specific utilities better than the bulk form of metals. Nanotechnology by means of specific traits of nanoparticles can be an identical valuable knowledge in various industry and science divisions. The noble metals like silver, gold, platinum, palladium, copper, zinc, selenium, titanium, and iron were used in synthesis of particles of nano-size. Chemical, physical, and biological ways have been used toward synthesis of various types of metal nanoparticles. The extensive potential applications of these nanoparticles made the green (biological or biogenic) synthesis by using bacteria, algae, actinomycetes, fungi, and plants. In the plant-based synthesis, several extracts (leaves, bark, stem, shoots, seeds, latex, secondary metabolites, roots, twigs, peel, fruit, seedlings, essential oils, tissue cultures, gum) are used. Therefore, the current review especially focuses on synthesis particularly plant-intermediated biosynthesis of metal nanoparticles and their classification.
