Huifeng Qian

Highly luminescent CdTe quantum dots prepared in aqueous phase as an alternative fluorescent probe for cell imaging

In this paper, our main aim is to explore the feasibility for application of luminescent CdTe quantum dots prepared in aqueous phase to live and fixed cell imaging. The highly luminescent CdTe quantum dots (QDs) were first prepared in aqueous phase using 3-mercaptopropionic acid (MPA) as a ligand, and then were covalently coupled to a plant lectin (UEA-1) and antibody anti-von Willebrand factors (anti-vWF) as fluorescent probes. Two probes QD-UEA-1 and QD-anti-vWF) were able to specifically bind the corresponding cell membrane receptor and cytoplasm immunogen, respectively. The good cell images were obtained in live cells and fixed cells using laser confocal scanning microscopy. Our preliminary results illustrated that CdTe QDs prepared in water phase were highly luminescent, water-soluble, stable, and easily conjugated with biomolecules since their surface were coated with MPA containing free carboxyl group. We predict that QDs prepared in water phase will probably become an attractive alternative probe in cellular imaging and bio-labeling.

Rapid synthesis of highly luminescent CdTe nanocrystals in the aqueous phase by microwave irradiation with controllable temperature

In this paper, we present a new method for rapid synthesis of high quantum yield CdTe nanocrystals in the aqueous phase by microwave irradiation with controllable temperature.

Sizes of water-soluble luminescent quantum dots measured by fluorescence correlation spectroscopy

In this paper, fluorescence correlation spectroscopy (FCS) was applied to measure the size of water-soluble quantum dots (QDs). The measurements were performed on a home-built FCS system based on the Stokes-Einstein equation. The obtained results showed that for bare CdTe QDs the sizes from FCS were larger than the ones from transmission electron microscopy (TEM). The brightness of QDs was also evaluated using FCS technique. It was found that the stability of the surface chemistry of QDs would be significantly improved by capping it with hard-core shell. Our data demonstrated that FCS is a simple, fast, and effective method for characterizing the fluorescent quantum dots, and is especially suitable for determining the fluorescent nanoparticles less than 10nm in water solution.