Ligand exchange
in lipid membrane embedded CdSe QDs. Ligand exchange
for CdSe QDs encapsulated within DOPC (a–e) and DSPC (f–j)
vesicles. Colocalization of fluorescence emission from NBD-PC (a),
QDs (b), and Cy5 (c) in individual DOPC vesicles indicates ligand
exchange of QDs within fluid lipid vesicles (d and e). (f–j)
Shows representative fluorescence microscopy images of QDs embedded
within DSPC vesicles. (f) and (g) display colocalization, but (h)
shows no localization with the QD embedded within the DSPC vesicles,
indicating the lack of ligand exchange (i and j). The Cy5 signal in
(h) (dotted circle) is due to the nonspecific adsorption of the ligand
on the surface of glass, which is also shown in the DOPC-CdSe sample
in (c) (dotted circles).