Synthesis of Water-Soluble, Cadmium-Free Quantum Dots for Bioimaging
Luminescent semiconductor nanocrystals or quantum dots (QDs) show great potential as fluorescent probes for molecular and in vivo imaging. While traditional cadmium-containing QDs have been widely used in biomedical research, diagnostics, and drug delivery, the cytotoxicity arising from the release of Cd2+ ions caused by the degradation of the surface coating is deemed to be a shortfall of cadmium-based QDs for long-term cellular and in vivo imaging. Here we report a robust synthesis of transition-metal doped zinc selenide QDs in an aqueous solution. The resulting QDs exhibit near-infrared tunable fluorescence emissions, which coincide with the biological window of transmission to offer high signal-to-noise for fluorescence imaging of cells and small animals.
Chai Hoon is a third year graduate student in MEMS Dept. She has earned a B.Sc. in Chemistry from National University of Singapore and a M.Sc. degree from MEMS Dept at Duke University. She is currently working with Dr. Kam Leong in the field of Nanomedicine.