Development of FRET-Based Assays in the Far-Red Using CdTe Quantum Dots

[摘要] Colloidal quantum dots (QDs) are now commercially available in a biofunctionalized form, and Förster resonance energy transfer (FRET) between bioconjugated dots and fluorophoreswithin the visible range has been observed. We are particularly interested in the far-red region, as from a biological perspective there are benefits in pushing to∼700 nm to minimize optical absorption (ABS) within tissue and to avoid cell autofluorescence. We report on FRET between streptavidin- (STV-) conjugated CdTe quantumdots, Qdot705-STV, with biotinylated DY731-Bio fluorophores in a donor-acceptor assay. We alsohighlight the changes in DY731-Bio absorptivity during the streptavidin-biotin binding process whichcan be attributed to the structural reorientation. For fluorescence beyond 700 nm, different alloycompositions are required for the QD core and these changes directly affect the fluorescence decaydynamics producing a marked biexponential decay with a long-lifetime component in excess of 100nanoseconds. We compare the influence of the two QD relaxation routes upon FRET dynamics in thepresence of DY731-Bio.

[学科分类] 基础医学