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.