|
|||||
|
|
Photostability comparison of CdTe and CdSe/CdS/ZnS quantum dots in living cells under single and two-photon excitations |
|
| Authors: | Qi-Feng Ma Xi wu Yang Yue |
| Institution: | a State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, PR China b Department of Optical Science and Engineering, Fudan University, Shanghai 200433, PR China c National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy Science, Shanghai 200083, PR China |
| Abstract: | The photostability is an outstanding feature of quantum dots (QDs) used as fluorescence probes in biological staining and cell imaging. To find out the related factors in the QD photostability, the photobleaching of naked CdTe QDs and BSA coated CdSe/CdS/ZnS QDs in human hepatocellular carcinoma (QGY) cells and human nasopharynx carcinoma (KB) cells were studied under single photon excitation (SPE) and two-photon excitation (TPE). In these two cell lines the cellular QDs were irradiated by a 405 nm continuous wave laser for SPE or an 800 nm femto-second (fs) laser for TPE. The QD photobleaching with the irradiation time was found to fit a biexponential decay. The fast decay plays a dominant role in the bleaching course and thus can be used as the parameter to quantitatively evaluate the QD photostability. The TPE decreased the QD photobleaching as compared to SPE. The BSA coated core/shell QDs had improved the photostability up to 4-5 times than the naked QDs due to the shielding effect of the QD shell. Therefore, it is better to use core/shell structured QDs as the fluorescence probe combining with a TPE manner for those long-term monitoring studies. |
| Keywords: | Quantum dots Photostability Living cells Single photon excitation Two-photon excitation |
| 本文献已被 ScienceDirect 等数据库收录！ | |