In this paper, we use SCS to characterize the hydrodynamic
sizes of two different shapes of GNPs (GNSs and GNFs), with
two different surface chemistries (with and without PEG) and
different sizes (20, 30, and 50 nm). We explore the scattering
properties of these GNPs at two wavelengths, close and far
from their plasmon resonances. For that we integrate the
scattered signal of GNPs during 300 s at different excitation
powers. As predicted by Mie theory, we demonstrate that the
increase in GNSs size leads to the increase of the scattered
intensity with the excitation power. In the case of GNFs, we
observe a large increase of the scattered signal due to their
specific surface morphology. Such results make this type of
nanoparticles a better candidate for both cell imaging and
photothermal therapy.