Four-photon-excited fluorescence resonance energy transfer in an aqueous system from ZnSe:Mn/ZnS quantum dots to hypocrellin A.

In this work, we established a fluorescence resonance energy transfer (FRET) system between ZnSe:Mn/ZnS quantum dots and Hypocrellin A (HA, a photosensitizer used for photodynamic therapy of cancer) in aqueous solution, excited by four-photon. Here, the QDs are the donors and the HA are the acceptors. The four-photon-excited fluorescence resonance energy transfer spectrum was obtained under 1300nm femtosecond laser pluses.