'Giant' multishell CdSe nanocrystal quantum dots with suppressed blinking: Novel fluorescent probes for real-time detection of single-molecule events

Jennifer A. Hollingsworth, Javier Vela, Yongfen Chen, Han Htoon, Victor I. Klimov, Amy R. Casson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)

Abstract

We reported for the first time that key nanocrystal quantum dot (NQD) optical properties-quantum yield, photobleaching and blinking-can be rendered independent of NQD surface chemistry and environment by growth of a very thick, defect-free inorganic shell (Chen, et al. J. Am. Chem. Soc. 2008). Here, we show the precise shell-thickness dependence of these effects. We demonstrate that 'giant-shell' NQDs can be largely non-blinking for observation times as long as 54 minutes and that on-time fractions are independent of experimental time-resolution from 1-200 ms. These effects are primarily demonstrated on (CdSe)CdS (core)shell NQDs, but we also show that alloyed shells comprising CdxZn1-xS and terminated with a non-cytotoxic ZnS layer exhibit similar properties. The mechanism for suppressed blinking and dramatically enhanced stability is attributed to both effective isolation of the NQD core excitonic wavefunction from the NQD surface, as well as a quasi-Type II electronic structure. The unusual electronic structure provides for effective spatial separation of the electron and hole into the shell and core, respectively, and, thereby, for reduced efficiencies in non-radiative Auger recombination.

Original languageEnglish
Title of host publicationColloidal Quantum Dots for Biomedical Applications IV
DOIs
Publication statusPublished - Jun 16 2009
EventColloidal Quantum Dots for Biomedical Applications IV - San Jose, CA, United States
Duration: Jan 24 2009Jan 26 2009

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume7189
ISSN (Print)1605-7422

Other

OtherColloidal Quantum Dots for Biomedical Applications IV
CountryUnited States
CitySan Jose, CA
Period1/24/091/26/09

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Keywords

  • Core-shell
  • Nanocrystal quantum dot
  • Non-blinking
  • Suppressed blinking

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

Cite this

Hollingsworth, J. A., Vela, J., Chen, Y., Htoon, H., Klimov, V. I., & Casson, A. R. (2009). 'Giant' multishell CdSe nanocrystal quantum dots with suppressed blinking: Novel fluorescent probes for real-time detection of single-molecule events. In Colloidal Quantum Dots for Biomedical Applications IV [718904] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 7189). https://doi.org/10.1117/12.809678