Eco-friendly methods of gold nanoparticles synthesis

Background: Owing to the importance of metallic nanoparticles, different researches and studies have been induced to synthesize them in many ways. One of the ways that paid attention last years is the green synthesis methods of nanoparticles or the so-called ''eco-friendly methods''. The most common sources that has been used for green synthesis of nanoparticles are plants, leaves, fungi and microorganisms. The green synthesis methods are widely used because they are inexpensive, usable, and nontoxic. Moreover, plant extracts are rich in reducing and capping agents. Methods: In the present review, green synthesis methods of gold nanoparticles (AuNps) using Chitosan, Klebsiella pneumoniae, Magnolia Kobus, Elettaria cardamomum (Elaichi) aqueous extract and other agents as a reducing/capping agents will be discussed in details. Moreover, we will make a comparison between different green routes of synthesis and the characterization of the obtained nanoparticles from each route. Results: The characterization and applications of the prepared GNPs from different routes are reviewed. Conclusion: The utilization of gold nanoparticles has been advocated because of their high bio-comptability, administration in clinical applicability and in diverse aspects of life. It seems that plants are good candidates for nanoparticles production because they are inexpensive, available and renewable sources in addition, it is too simple to prepare extracts from them. Moreover, the great diversity in the types and amounts of reducing agents from plant extracts is responsible for the effortless generation of metallic nanoparticles of various shapes and morphologies. © 2019 Bentham Science Publishers.