Efficient phase transfer of hydrophobic CdSe quantum dots: From nonpolar organic solvent to biocompatible water buffer

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), photoluminescence (PL) spectroscopy, fluorescence mapping, and differential scanning calorimetry (DSC), respectively. TEM images showed that QDs have been encapsulated in the liposomes. PL spectroscopy indicated that hydrophobic CdSe QDs within liposome basically retain optical properties of free nanocrystals. Fluorescence mapping successfully showed intensity distribution of liposome entrapped luminescence QDs (QD-liposome). DSC data indicated that the enthalpy (ΔH) of the QD-liposome increased, suggesting the enhancement of hydrophobic interaction between lipid hydrophobic chains and organic ligands on the surface of QDs.