A: Pictures of test tubes containing the bacteria M. pelagius cells before (test tube 1) and during incubation in an aqueous of HAuCl
solution at pH 7.8. B: UV–Vis absorption spectra of gold nanoparticles after the incubation of M. pelagius in 1x10-3 M aqueous HAuCl4 solution at 7.8 pH. The numbers (1,2,3 and 4) indicates the absorption spectra taken at different time intervals 24,48,72 and 96 respectively. C, D: TEM images of gold nanoparticles produces by the reaction of 1x10-3 M aqueous HAuCl4 solution with bacteria M.pelagius biomass at 7.8 pH. Particles are mostly spherical with nano triangles also present (arrow). Bar = 20 nm (A) and 10 nm (B).