Structural and single particle and ensemble spectroscopic studies of various core-shell biofunctional quantum dots: Implications for biological imaging

by Heyes, Colin D.

A range of core-shell quantum dot systems such as CdSe-ZnS, CdTe-ZnSe, CdSe-CdS-ZnS and CuInS2-ZnS have been synthesized and studied at the ensemble and single particle level. Optical and structural properties are analyzed by a combination of time-resolved ensemble and single mol. fluorescence spectroscopy and high resoln. TEM and HAADF-STEM combined with on-particle elemental anal. I will discuss the influence of the core-shell interface on the radiative and non-radiative exciton recombination rates and the coupling to the external environment, specifically biol.-relevant environments. Single mol. fluorescence properties such as blinking, dark fraction formation and single QD lifetimes are compared to the ensemble fluorescence observations. Applications of the various core-shell systems in single mol. FRET, FLIM and time-gated intracellular imaging are also discussed.