Gold nanoparticles were prepared following the method of Gopu
et al. [8]. Briefly, 95mL of an aqueous chloroauric acid solution containing
5 mg of Au was brought to boil and then 5 mL of 1% sodium citrate
solution was added to the boiling solution. The color of the solution
first changed to bluish, then to purplish and eventually to ruby red.
The solution was further boiled for 30 min and left to cool to ambient
temperature [8]. TEMimage shows that spherical particleswith a diameter
of 9 ± 2 nm Fig. 2. The particle size distribution curve for synthesized
GNs. is given in Fig. 3.