UV–vis spectra recorded as a function of reaction time of an aqueous solution of 1 mM HAuCl4 with the filtrate of the fungal biomass. The spectra show a sharp absorption λmax 540 at 48 h reaction periods, which intensifying with the 72 h reaction time. The inset shows vials containing the filtrate of A. clavatus collected during the reaction period, rapid change in colour pattern due to SPR are clearly visible.
Verma et al. Nanoscale Res Lett 2011 6:16 doi:10.1007/s11671-010-9743-6