Figure 2.

Photostability tests of the CdS/dendrimer and polyphosphate-stabilized (PPS) nanoparticles. The sample was contained in a standard 1 cm × cm (4 mL) cuvette. The incident power was 30 mW at 405 nm from a frequency-doubled Ti:sapphire laser, 80 MHz, 200 fs, which was focused with a 2 cm focal length lens. Also shown is the intensity from fluorescein, pH 8, under comparable conditions. When illuminated with the output of a 450 W xenon lamp (385 nm for blue and 405 nm for red nanoparticles) there was no observable photobleaching.