2.2. Gold Nanoparticles

Gold nanoparticles of 5 nm (Cat. No. MKN-Au-005), 20 nm (MKN-Au-020), and 50 nm (MKN-Au-050) diameter (Au concentration of 0.01%) which were stabilized with chloroauric acid (HAuCl₄) were purchased from MK Impex Corporation, Missisauga, ON, Canada. The stock solutions of GNPs were kept refrigerated. The size and morphology of the GNPs were evaluated by transmission electron microscopy (TEM) (Model 1011CX, JEOL, Tokyo, Japan) and are shown in Figure 1. The small and medium sized GNPs (5 and 20 nm) had a round shape, whereas the shape of the larger sized GNPs (50 nm) appear as hexagonal (Figure 1).

Evaluation of the size and shape of the GNPs using transmission electron microscopy. Scale bar = 50 nm.