Figure 2: Characterization of Au NPs after suspension in 2.5 mm sodium citrate. (a) Transmission electron microscopic (TEM) image of 40 nm Au NPs. Inset shows a single particle at higher magnification (bar 20 nm). Box indicating potential of these Au NP suspensions (in 2.5 mM sodium citrate) and particle number per mL. (b) Dynamic Light Scattering (DLS) analysis of Au nanoparticle suspension showing single population of Au nanoparticles, having 40 nm hydrodynamic diameter.