Mycogenesis of silver nanoparticles by different Aspergillus species

The bio-synthesis of nanomaterials is emerging as an innovative methodology, which is comparatively eco-friendly and inexpensive. Among dierent microbes, the role of fungi has been proved considerably promising in the in-vitro synthesis of nanomaterials. In this study, the comparative ecacy of four dierent species of Aspergillus (A. fumigatus, A. niger, A. avus and A. terreus) was investigated for the synthesis of silver nanoparticles (AgNPs). Initially, the synthesis was monitored through changes in coloration (yellow to dark brown) of the reaction solution containing AgNO3 reacted with the fungal biomass, of each fungi for 96 hours (hr) at 28C. The UV-visible spectra of the reaction mixture taken at dierent times showed a gradual change in absorbance between 400-420 nm, corresponding to changes in the surface plasmon resonance of the Ag metal. Comparatively, A. fumigatus showed a higher rate of nanoparticle synthesis than the other fungi. X-Ray Diraction (XRD) spectra showed peaks of various intensities, with respect to the angle of diraction (2), thus, revealing the crystalline nature of AgNPs. Nanoparticles fabricated through A. fumigatus (5-18 nm) and A. avus (13-26 nm) exhibited more drift towards monodispersity, which was relatively higher (6-70 nm) than in the other two fungi. Transmission Electron Microscopy (TEM) further conrmed the conguration of AgNPs in the range of 3-80 nm.