Kelly Stewart - DNA-Passivated CdS Nanocrystals: Luminescence, Bioimaging and Toxicity Profiles

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      Publication Details (including relevant citation   information):

      N.Ma, J.   Yang, K.M.   Stewart,and S.O. Kelley,   Langmuir 2007 23, 12783


      A class of luminescent semiconductor quantum dots is described   that exhibit low cellular toxicity without the use of bulky   surface coatings. Nucleic acids, either in the form of   mononucleotides or DNA oligonucleotides, are used as a ligand   system in the aqueous synthesis of CdS nanocrystals. The   materials produced exhibit diameters on the order of 4 nm and   luminescence in the range of 500−700 nm. Importantly, DNA−CdS is   stable in buffers of high ionic strength for many hours. When   tested for toxicity in HeLa cells, minimal decreases in cell   viability were observed, indicating that the DNA−CdS nanocrystals   are highly stable in biological media. Uptake of the nanocrystals   into unfixed mammalian cells was tested, and internalization was   observed. The results reported indicate that the use of DNA as a   ligand system for water-soluble semiconductor nanocrystals   represents a worthwhile strategy for the production of new   biological imaging agents.

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