An Overview of the Green Road to the Synthesis of Nanoparticles

The world today is witness to the exponential rise of nanotechnology in our daily lives with a vast number of applications in energy, medicine, food, water, cosmetics and drugs. The attractive properties of materials in the nanoscale have brought to light many new discoveries and innovative applications of nanoparticles (NPs). The progress and implementation of this new and exciting technology requires caution especially during nanoparticle production and synthesis. The fabrication of these all important NPs should be done in a clean, cheap, sustainable and safe manner with minimum risk to health and environment. This article reviews and reports eco-friendly, sustainable and energy efficient green methods of synthesizing NPs, with low environmental pollution and health hazards. Our aim is to highlight and summarize the use of green synthesis methods that use biological units, namely, plants and microorganisms (bacteria, yeast and fungi) for the production of inorganic NPs, with a focus on research works during the last five years. The added advantage of disease inhibition of NPs produced using the green approach, due to their excellent antibacterial, antifungal and antitumor properties, has also been discussed and illustrated with specific examples from literature.