Fig. 1. Characterization of CdTe/CdS/ZnS core/shell/shell QDs. (a) Absorption and photoluminescence spectra of CdTe/CdS/ZnS QDs (inset: photographs of CdTe/CdS/ZnS QDs solutions under ambient light (left) and UV light (right)). (b) Low magnification and high-resolution (inset) images of CdTe/CdS/ZnS QDs (scale bars are 50 nm and 5 nm respectively). (c) Hydrodynamic diameter of CdTe/CdS/ZnS QDs measured by DLS. (d) Photostabilities of CdTe/CdS/ZnS QDs, CdTe QDs, and Ce6 molecules excited with a 405 nm laser (110 mW). (e) Cell viabilities of MCF-7 cells incubated with CdTe/CdS/ZnS QDs and CdTe QDs for 1 and 12 hours.