Enhanced gold nanoshell scattering contrast using angled fiber probes

Gold nanoshells are positioned to become a scattering-based contrast agent to improve the reflectance signals of nanoshell-targeted tissue. However, our study shows that a greater enhancement of nanoshell-induced reflectance signals can now be achieved when angularly oblique fiber geometries are used in place of the conventional orthogonal fiber geometry. This important finding was confirmed by conducting two experiments. First, diffuse reflectance spectra were collected from nanoshell-infused polystyrene phantoms at 0, 10, 20, 30 and 40 degree collection angles. At the 40 deg. fiber angle, the nanoshell-induced reflectance contrast, with respect to the native polystyrene phantom, is significantly increased. Based on these results, a reflectance study was then conducted for human cervical tissue treated with gold nanoshells at the 0 and 40 degree collection angles. Again, at the 40 deg. fiber angle, the signal level of the nanoshell-induced contrast in tissue is determined as statistically significant. Taken together, these results demonstrate that the use of the angularly oblique fiber geometry does significantly improve reflectance contrast.