Nov 5, 2009
Bio-highlighter: NIR-emitting alloyed quantum dots
Quantum dots (QDs) are a relatively new class of fluorescent probe that suit a variety of biotech applications thanks to their excellent fluorescent properties. A key area of interest is the use of QDs as a contrast agent for in vivo imaging. Their near-infrared (NIR)-emitting window is appealing for biological optical imaging because of the low tissue absorption and scattering effects in this emission range (650–900 nm). However, there have been many challenges in preparing high-quality NIR-emitting water-dispersible Qdots in an aqueous medium directly.
Now, Jun-Jie Zhu and his team from Nanjing University, China, have come up with a straightforward protocol for synthesizing CdSeTe alloyed quantum dots (A-QDs). The group has shown that the material can be used as an effective NIR-emitting probe for cell imaging and biosensing and has published its results in the journal Nanotechnology.
By changing the size and/or composition of these water-soluble A-QDs, the emission can be tuned from the visible to the NIR region (as shown in the image above).
Owing to the excellent NIR-emitting properties of the CdSeTe A-QDs, research is now underway to design and improve such "smart" materials for targeted and traceable drug delivery in cells and small animals. This research is supported by grants from the National Natural Science Foundation of China.
About the author
The work was performed at the Key Laboratory of Analytical Chemistry for Life Science (MOE), at Nanjing University, China. Dr Jun-Jie Zhu is the professor of chemistry, and vice dean of the School of Chemistry and Chemical Engineering, Nanjing University. Dr Jianrong Zhang is the professor of chemistry at Nanjing University. Guoxi Liang is a PhD student in the Division of Analytical Chemistry at Nanjing University. Miaomiao Gu is an MS student at Nanjing University.