Figure 2.

Salt stability of modified and unmodified nanoparticles measured using UV-Vis absorbance spectroscopy. Salt concentration was increased using 2 µl for unmodified nanoparticles and 15 µl of 4.11 mol/l NaCl every 15 minutes. Wavelength scans of (a) 5 nm unmodified Au nanoparticles and (b) Au-Cap nanoparticles in solution with increasing NaCl concentration. Shaded area under the curves in a and b were used to calculate aggregation parameter. (c) Aggregation parameter plotted with mean ± SD for n = 3 for increasing NaCl concentration for 5 nm unmodified Au and Au-Cap. Aggregation parameter of unmodified Au show a large increase with small increases in NaCl concentration.