Photoluminescent Silicon Quantum Dots : Chromophore for Biological Imaging

Due to their strong luminescence,Quantum dots of group II/VI such as CdSe quantum dots are well-known, and substantial research has been conducted on these systems .There have, however, been concerns over the toxicity of these quantum dots in the human body. It has been reported in past that cell damage could be caused by an uncoated CdSe core under UV excitation. Because of their low toxicity and also inexpensive nature, silicon nanoparticles emerges as an ideal candidate for biological fluorescence imaging. In a recent article in JACS, researchers from New Zealand and Japan suggested the synthesis of amino-terminated silicon quantum dots made in reverse micelle system and capped with allylamine using a platinum catalyst. Their newly developed technique of surface modification is multistepped based on the chemistry of the terminal double bond on the surface to achieve the target functionalities. Thus formed Silicon quantum dots were characterized by transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). The capping of the silicon quantum dots has been fully characterized using nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The results from cytotoxicity studies indicate that toxicity is dependent on the surface functionality and that the silicon quantum dots as prepared have potential in biological applications such as bioimaging. In summary, silicon quantum dots opens new doors in the field of biological imaging.
Ref: J. Am. Chem. Soc., Article ASAP, DOI: 10.1021/ja906501v