Different strategies to synthesise gold nanoparticles and their applications

Nanotechnology is a science which deals with particles in the nanometre size range. They made from different metals such as copper, silver, zinc, gold, platinum etc. Gold nanoparticles have been synthesised at large scale due to their wide applications in diagnostics, treatment, food safety and forensic areas. Nanoparticles are synthesised using different strategies such as chemical synthesis, biogenic synthesis and via biological sources like plants, bacteria, algae, fungi. They are used because of their low toxicity and biocompatibility. Chemical synthesis methods have problems like toxicity so the stimulus of synthesis has shifted from physical and chemical processes towards 'green' chemistry and bioprocesses. Use of plant extracts has been increased widely for synthesis of gold nanoparticles. Microorganisms like bacteria, yeast, fungi, algae and blue green algae have been used mainly for synthesising gold nanoparticles.