Cytodiagnostics Gold NanoUrchins have unique optical properties compared to spherical gold nanoparticles
of the same core diameter. The spiky uneven surface causes a red shift in the surface plasmon peak and a larger enhancement of the electromagnetic field at the tips of the Gold NanoUrchin spikes compared to that of a spherical particles. As an example, 100nm spherical gold nanoparticles
have an SPR peak at 570nm while 100nm Gold NanoUrchins
have a SPR peak at around 680nm, figure 1.
Figure 1. Left) UV-VIS spectra of 100nm Gold NanoUrchins (blue) and 100nm standard gold nanoparticles (green). Note the red-shift in the SPR-peak. Right) UV-VIS spectra of Gold NanoUrchins ranging in size from 50nm to 100nm in diameter.