Biosynthesis of gold nanoparticles using plant extracts.

Because of the widespread use of metallic nanoparticles in biology, pharmaceuticals, and medicine, biosynthesis methods are being considered to prepare these nanoparticles. Among biosynthesis methods mentioned in the literature, the use of plant extracts has gained great importance due to the fact that most of the plants are generally inexpensive, available, and nontoxic. Moreover, plant extracts are rich in different types of reducing and capping agents. Therefore, these methods have a high potential for scale-up and can produce nanoparticles in different morphologies. In this paper, different green methods used to prepare metallic nanoparticles and the types of characterization methods for their identification have been comprehensively explained. Since gold nanoparticles are considered more biocompatible than other metallic nanoparticles, research studies performed on green synthesis of gold nanoparticles using plant extracts and different applications of these nanoparticles have been reviewed and discussed.