Au nanorods can be used for long-term cell imaging?

The photostability of Au nanorods in human hepatocellular carcinoma cells under two-photon excitation was investigated to evaluate their potential in cell imaging. The photoluminescence images of the intracellular Au nanorods under the two-photon excitation of an 800 nm femtosecond laser were photobleached rapidly, which is due to the melting of Au nanorods. The images lost their brightness for more than 50% after 15 micrograph scans for the nanorod incubation concentrations of 10, 20, and 40 pM. The confocal reflectance image can prevent the image photobleaching and thus is suitable for long-term cell imaging with Au nanorods.