Luminescent CuIn(SeS)2 Nanocrystals for Diagnostic Imaging

Semiconductor quantum dots could potentially be used as near-infrared fluorescent probes that are brighter and more photostable than organic dyes. However, the toxicity of the components of near-infrared (NIR) emitting II−VI and IV−VI nanocrystals  (Cd, Pb, Hg, etc.) is an obstacle to clinical due to their toxicity. We report a method to synthesize copper indium selenium sulfide (CuIn(SeS)₂) nanocrystals with strong photoluminescence in the visible to NIR. The hydrophobic nanocrystals are encapsulated with an amphiphilic polymer, which enables dispersion in aqueous media while retaining high quantum yield.   We demonstrate the potential of these nanocrystals for use as a noninvasive imaging probe by performing in-vivo fluorescence imaging in mice.