Silica coated gold nanorods for imaging and photo-thermal therapy of cancer cells.

Due to their efficient conversion of absorbed light energy to heat gold nanorods have been proved to be an amazing tool for minimally invasive photo-thermal cancer therapy. The present in vitro study demonstrates the ability of silica coated Au nanorods to function as a dual probe for cancer-cell therapy and imaging without any toxic side-effects. HeLa cells were incubated with silica coated Au nanorods and imaged inside the cell just after 1 hour of incubation by a dark field set up due to strong surface enhanced Raman scattering. To induce hyperthermia, silica coated Au nanorod incubated HeLa cells were illuminated with a diode laser (671 nm, 200 mW, 10 min). Cell destruction was observed even at a very low dose of nanorods, whereas none was observed in the absence of nanorods. Silica coated Au nanorods thus offer a promising, novel class of selective photo-thermal agents for cancer therapy and diagnosis.