Preparation of water-soluble quantum dots and their self-assembly with chitosan derivatives

Water-soluble CdTe quantum dots(QDs) were prepared by using 3-mercaptopropionic acid as the stabilizer, and their preparation parameters were optimized. Self-assembling of QDs with chitosan and folic acid (FA) and poly (ethylene glycol) (PEG) modified chitosan via electrostatic interaction was also investigated. The results demonstrate that fluorescence intensity of chitosan/QDs complex was much higher than that of QDs themselves. The complex shows a clear core/shell structure, and QDs were located in the core. The modified chitosan/QDs complexes were smaller and more uniform than those of unmodified chitosan.