Figure 4.

Hydrodynamic size (gray) and diffusion coefficient D (black) of nanoparticles at pH 4 and pH 7 and free Cy3 dye at pH 4. Larger hydrodynamic size at pH 7 indicates the nanoparticles specific size distribution. In addition, diffusion coefficients and hydrodynamic size of nanoparticles and free Cy3 dye at pH 4 are in the same range, suggesting dissolution of the nanoparticles at pH 4. *p<0.0001 for pH 4 vs. pH 7. (Adapted with permission from ref. [115]. Copyright 2008 American Chemical Society)