Luminescent gelatin nanospheres by encapsulating CdSe quantum dots.

Quantum dots (QDs) have been encapsulated within gelatin nanoparticles (GNPs), which gives GNPs fluorescent properties and improves the biocompatibility of QDs. Hydrophilic CdSe QDs were produced through thermodecomposition following the ligand-exchange method, and were then encapsulated in GNPs. The results of high-resolution transmission electron microscopy and transmission electron microscopy show that CdSe QDs and QDs-encapsulated GNPs (QDs-GNPs) have average diameters of 5 ± 1 and 150 ± 10 nm, respectively. Results of both high-resolution transmission electron microscopy and confocal laser scanning microscopy indicate that CdSe QDs are successfully encapsulated within GNPs. The QDs-GNPs have distinctive fluorescent properties with maximum emission at 654 nm, with a 24 nm red-shift compared with hydrophilic mercaptoundecanoic acid (MUA)-modified QDs. In addition, an in vitro cytotoxicity test shows that QDs-GNPs do not have any toxic effect on cells. It is expected that QDs-GNPs might be an excellent candidate as a contrast agent in bio-imaging.