Green synthesis of silver nanoparticles using marine-derived fungus Aspergillus niger

The objective of this study was to examine the biosynthesis potential of facultative marine fungus Aspergillus niger (isolated from coastal waters of Gulf of Cambay, West Coast of India) for the preparation of silver nanoparticles. When fungus was challenged with different concentrations of silver nitrate (0.25-1 mM), within 24 h, it synthesised extracellular silver nanoparticles. The biosynthesised nanoparticles were characterised by analytical techniques through UV-visible spectrophotometry, transmission electron microscopy and Fourier transform infrared spectroscopy. The particles were found to be spherical with size range of 5-26 nm. Laser optical speckles were also observed for these nanoparticles, which is the first ever report of laser optical speckles from biosynthesised silver nanoparticles using marine-derived fungus.