Figure 2.

The flasks containing the biomass of the Aspergillus clavatus biomass in sterile distilled water (Control) and in aqueous solution of 1 mM HAuCl4 after the reaction of 72 h (the biomass colour changed into dark purple). Inset shows the pictures of fermentation broth of Aspergillus clavatus challenged by 1 mM HAuCl4.

Verma et al. Nanoscale Res Lett 2011 6:16   doi:10.1007/s11671-010-9743-6