The standard deviation of all nanoparticle sizes in a size
distribution is the error in d, which is stated in the text and the
figures of this paper. The number density of the particles was calculated from the total amount of gold used for the synthesis,the measured particle diameter, and the volume of the solution
in which they were synthesized. Thus, the synthesis reactions
were assumed to be complete, since excess amounts of reducing
agent were used. This assertion was consistent with UV-vis
spectroscopy in the wavelength range of 200-300 nm where no
residues of H4AuCl4 could be detected.