Multicolored cell imaging with bioconjugated fluorescent quantum dots

Photoluminescent quantum dots (QDs) have been extensively used in biomedical research for sensing, imaging and disease therapy. In this contribution, we demonstrate the use of bioconjugated cadmium telluride (CdTe) QDs as fluorescent optical probes for targeted in vitro cell imaging. A co-surfactant system of mercaptopropionic acid (MPA) and Cysteine (Cys) mixture were introduced for the synthesis of CdTe QDs in aqueous phase. The QDs as synthesized possess narrow emission profile and the colour is size tunable over the visible range. Multichannel imaging of cancer cells using different QD-conjugates were demonstrated. Specificity of cancer cell labelling was obtained by conjugating the QDs with bio-functional molecules such as folic acid and transferrin. This work suggests that bioconjugated CdTe QDs can be used for high-contrast in vitro cell imaging and cancer cell detection.