Handbook of Biomedical Optics

Nanoparticles for Targeted Therapeutics and Diagnostics 707

for highly sensitive detection of labeled cells, even in the pres-

ence of single unbound gold nanoparticles. e spectral shi

associated with spheres was also used to follow EGFR tracking

in live cells following EGF stimulation (Figure 32.1) (Aaron et al.

2009). Aaron et al. used live cell dark-eld microscopy to image

dynamic behavior of EGF receptors labeled with spherical gold

nanoparticles. Aer stimulation with a growth factor, the recep-

tors dimerize and are then internalized into endosomes inside

the cell, causing aggregation of the attached nanoparticles.

ese steps ...