Varied Potentials of Aspergillus Species in Synthesis of...

Conclusions To conclude, though use of Aspergillus species is common in synthesis of metal nanoparticles, these five species are not well studied. Among them, A. fischeri confirms a good quality production of AgNPs at an incredibly low concentration of salt solution used but with more number of bigger sized particles. However, efforts are underway to optimize the conditions in the process to obtain a good size and shape morphology. Also, understanding the protein–nanoparticle interactions during the synthesis mechanism shall guide us to the possibility of utilizing the present system as future ‘‘nano-factories’’. We aim to purify and characterize the proteins to comprehend their mode of action and possible interactions with silver†¦show more content†¦Characterization Change in color was visually observed in the silver nitrate solution incubated with all five Aspergillus species. The bio reduction of Ag+ in the aqueous solutions was screened by sampling of aliquots at different time intervals. Absorption measurements were carried out on Thermo-scientific UV-Visible Spectrophotometer from 200-800nm, at a resolution of 1 nm. A part of the dried powdered sample was analysed by X-ray diffractometer as a preliminary confirmative method of the presence of silver nanoparticles. The X-ray diffractometer (Rigaku Miniflex-11) was operated at a voltage of 30 kV and a current of 15mA with CuKÃŽ ± radiation (ÃŽ »=1.5406 Ã…) and at 2 theta angles, intensities were recorded from 6 °to 60 °. To know the size of synthesized silver nanoparticles (AgNPs), size distribution analysis was performed using dynamic light scattering in aqueous solution. The hydrodynamic size of the silver nanoparticles was obtained using a Zeta-sizer (Malvern) instrument applying a 660 nm laser. The software was optimized to report summary statistics based upon the intensity of light scattered. Two milliliter sample volumes from each nanosilver dispersion were loaded into glass cuvettes and summary statistics were obtained using triplicate 2 minutes analyses (total analysis time=6minutes). For Fourier transform