Journal of the American Chemical Society 2012-03-14

Induction of pH sensitivity on the fluorescence lifetime of quantum dots by NIR fluorescent dyes.

Rui Tang, Hyeran Lee, Samuel Achilefu

Index: J. Am. Chem. Soc. 10th ed., 134 , 4545-4548, (2012)

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Abstract

Modulation of the fluorescence lifetime (FLT) of CdTeSe/ZnS quantum dots (QDs) by near-IR (NIR) organic chromophores represents a new strategy for generating reproducible pH-sensing nanomaterials. The hybrid construct transfers the pH sensitivity of photolabile NIR cyanine dyes to highly emissive and long-lifetime pH-insensitive QDs, thereby inducing a reproducible FLT change from 29 ns at pH >7 to 12 ns at pH <5. This approach provides an unparalleled large dynamic FLT range for pH sensing at NIR wavelengths.