Theranostics 2012; 2(3):295-301. doi:10.7150/thno.3912

Research Paper

Competitive Performance of Carbon “Quantum” Dots in Optical Bioimaging

Li Cao, Sheng-Tao Yang, Xin Wang, Pengju G. Luo, Jia-Hui Liu, Sushant Sahu, Yamin Liu, Ya-Ping Sun

Department of Chemistry and Laboratory for Emerging Materials and Technology, Clemson University, Clemson, South Carolina 29634-0973, USA.

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Cao L, Yang ST, Wang X, Luo PG, Liu JH, Sahu S, Liu Y, Sun YP. Competitive Performance of Carbon “Quantum” Dots in Optical Bioimaging. Theranostics 2012; 2(3):295-301. doi:10.7150/thno.3912. Available from

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Carbon-based “quantum” dots or carbon dots are surface-functionalized small carbon nanoparticles. For bright fluorescence emissions, the carbon nanoparticles may be surface-doped with an inorganic salt and then the same organic functionalization. In this study, carbon dots without and with the ZnS doping were prepared, followed by gel-column fractionation to harvest dots of 40% and 60% in fluorescence quantum yields, respectively. These highly fluorescent carbon dots were evaluated for optical imaging in mice, from which bright fluorescence images were obtained. Of particular interest was the observed competitive performance of the carbon dots in vivo to that of the well-established CdSe/ZnS QDs. The results suggest that carbon dots may be further developed into a new class of high-performance yet nontoxic contrast agents for optical bioimaging.

Keywords: Carbon dots, fluorescence, optical bioimaging, quantum dots.