Laser exposure of gold nanorods can induce intracellular calcium transients.

Uncoated and poly(styrene sulphonate) (PSS)-coated gold nanorods were taken up by NG108-15 neuronal cells. Exposure to 780 nm laser light at the plasmon resonance wavelength of the gold nanorods was found to induce intracellular Ca(2+) transients. The higher Ca(2+) peaks were observed at lower laser doses, with the highest levels obtained at a radiant exposure of 0.33 J/cm(2) . In contrast, the cells without nanoparticles showed a consistently small response, independent of the laser dose. These initial results open up new opportunities for peripheral nerve regeneration treatments and for more efficient optical stimulation techniques.