The development of an eco-friendly and reliable
process for the synthesis of gold nanomaterials
(AuNPs) using microorganisms is gaining importance in
the field of nanotechnology. In the present study, AuNPs
have been synthesized by bio-reduction of chloroauric acid
(HAuCl4) using the fungal culture filtrate (FCF) of Alternaria
alternata. The synthesis of the AuNPs was monitored
by UV–visible spectroscopy. The particles thereby
obtained were characterized by UV, dynamic light scattering
(DLS), X-ray diffraction (XRD), energy dispersive
X-ray (EDX) analysis, Fourier transform infrared (FTIR)
spectroscopy, atomic force microscopy (AFM) and transmission
electron microscopy (TEM). Energy-dispersive
X-ray study revealed the presence of gold in the nanoparticles.
Fourier transform infrared spectroscopy confirmed
the presence of a protein shell outside the nanoparticles
which in turn also support their stabilization. Treatment of
the fungal culture filtrate with aqueous Au? ions produced
AuNPs with an average particle size of 12 ± 5 nm. This
proposed mechanistic principal might serve as a set of
design rule for the synthesis of nanostructures with desired
architecture and can be amenable for the large scale
commercial production and technical applications
