Preparation of water soluble CdSe and CdSe/CdS quantum dots and their uses in imaging of cell and blood capillary

A novel method for the synthesis of water-soluble CdSe and CdSe/CdS quantum dots (QDs) under the assistance of high-intensity ultrasonic irradiation is reported. As-prepared CdSe/CdS QDs were characterized by X-ray powder diffraction and high-resolution transmission electronmicroscopy. The absorption and fluorescence emission spectra were measured to investigate the effect of CdS passivation on the electronic structure of the quantum dots. After the growth of CdS shell, the photoluminescence quantum yields of CdSe/CdS core–shell quantum dots increased three times more than that of the original CdSe QDs. The QDs were successfully used for the fluorescence imaging of cells and blood capillary.

A novel method for the synthesis of water-soluble small-size CdSe and CdSe/CdS quantum dots under high-intensity ultrasonic irradiation has been reported. As-prepared CdSe/CdS QDs were about 5.0 nm with narrow size distribution. The products were well formed which have been characterized by X-ray powder diffraction and high-resolution transmission electronmicroscopy as shown in Fig. a and b. Optical absorption and fluorescence emission spectra were used to probe the effect of CdS passivation on the electronic structure of the quantum dots. The photoluminescence quantum yields of CdSe/CdS core–shell quantum dots were larger than the original CdSe by around 3 times. The QDs were successfully used for the fluorescence imaging of cells and blood capillary.Figure optionsDownload high-quality image (147 K)Download as PowerPoint slideHighlights
► High-quality CdSe and CdSe/CdS QDs have be prepared with ultrasonic-assistance.
► The ultrasonic irradiation facilitate the formation of the CdSe/CdS QDs.
► The quantum yield of core–shell nanocrystals is about 3 times that of the original nanocrystals.
► The cell viability is relative to concentration of QDs and kinds of cells.
► Imaging of cells and tissues can be obtained by the strategy proposed.