Photostability comparison of CdTe and CdSe/CdS/ZnS quantum dots in living cells under single and two-photon excitations

► Core/shell QDs improve the photostability up to 4-5 times as compared to the naked QDs. ► TPE is better than SPE on decreasing the photobleaching of cellular QDs. ► Combination of core/shell QDs with the TPE has the advantage for long-term cell imaging.