脂溶性CdSe/ZnS量子点脂质体复合物的制备及表征

在油相中成功合成了脂溶性CdSe/ZnS核壳量子点纳米粒,粒径平均为4.5 nm,量子产率达29%,发射波长为540 nm。通过薄膜分散法,以蛋黄卵磷脂、胆固醇为膜材,将脂溶性的CdSe/ZnS核壳量子点包覆于脂质体磷脂双分子层中,由于磷脂分子的两亲性,使得脂溶性的CdSe/ZnS核壳量子点同时又具有亲水性。通过透射电镜对脂质体形态进行了表征,倒置荧光显微镜证实了发光CdSe/ZnS核壳量子点成功包埋于脂质体双分子层中,包裹的发光CdSe/ZnS核壳量子点具有更稳定的发光及抗光漂白性质。

Preparation and Characterization of Liposome Coated Hydrophobic CdSe/ZnS Core-shell QDs

In the organic phase, hydrophobic CdSe/ZnS core-shell quantum dots (QDs) were synthesized successfully using a free-phosphine and non-injecction method. The transmission electron microscopy (TEM) shows CdSe/ZnS core-shell nanocrstals with an average diameter of 4.5 nm. The fluo-rescence quantum yield of the QDs, calibrated with fluorescein using a 470 nm laser, was found to be 29%, which was greatly increased compared with bare CdSe QDs, indicating strong photoluminescence. The maximum emission wavelength of QDs was 540 nm at excitation of 410 nm. Through the thin-film evaporation method, using the L-α-phosphatidylcholine and Cholesterol, the hydrophobic CdSe/ZnS core-shell QDs were successfully embedded in the two-layer of liposome. As the amphipathy of phospholipid molecules, rendering the luminescent hydrophobic CdSe/ZnS core-shell QDs hydrophilia, CdSe/ZnS core-shell QDs can be transferred in water without extra surface combining reagents. The morphology of liposome was characterized by TEM using negatively stained method, the process of CdSe/ZnS core-shell QDs embedded in the phospholipid two-layer was confirmed by inverted fluorescent microscopy under the UV light. The result indicates that CdSe/ZnS core-shell QDs embedded in the phospholipid two-layer have more photostability and more resistant photobleaching.