The characterization and detection of GNPs are very
important steps before their bio-application. One of the recent
powerful techniques used to characterize GNPs is the scattering
correlation spectroscopy (SCS). As fluorescence correlation
spectroscopy (FCS), the SCS technique is based on the
analysis of intensity fluctuations within a well-defined confocal
volume (∼1 fL). The correlation curve is directly related to the
hydrodynamic radius of molecules or nanoparticles, to
their diffusion coefficient, concentration and shape. The
SCS is very sensitive to GNPs morphology and brightness since
the scattering intensity depends on the GNPs volume.