CdSe semiconductor QDs with diameters ranging between 1.5 and 8nm exhibit strong and tunable luminescence. They have been widely investigated because of their potential use in sensors

laser materials

thin film light-emitting devices (LEDs)

and biological labels. Among numerous possible applications of CdSe nanoparticles

biological labeling will be pointed out. However

highly luminescent CdSe nanocrystals were usually synthesized with hydrophobic organic capping agents

such as trioctylphosphine/trioctylphiosphine oxide (TOP/TOPO)

which limits their applications in biology. To overcome this limitation

several synthesis strategies have been used. This work presents that hydrophobic CdSe quantum dots (QDs) were successfully transferred from nonpolar organic solvent to biocompatible water buffer by liposome encapsulating technology. And this result has been confirmed via transmission electron microscopy (TEM)

fluorescence mapping

and photoluminescence (PL)

respectively. TEM image showed free CdSe QDs are spherical and nearly monodispersed

having an average diameter of 3nm. Average size of QD-liposome is approximately 20nm. TEM images showed that QDs have been encapsulated in the liposome. Fluorescence mapping successfully showed the luminescence intensity distribution of liposome-entrapped QDs (QD-liposome). Photoluminescence indicated that QDs-Lip basically retain optics quality of free quantum. This phenomenon can be attributed to liposome transfer with TOPO molecules that stabilize the surface of QDs

via hydrophobic interaction between double molecule chain of lipid with CdSe surface on the TOPO ligand

form a bilayer structure with TOPO molecules that stabilize the surface of QDs

keep CdSe exist environment. As a result

QDs-Lip possesses high emission efficiency.