Effect of the shell on the blinking statistics of core-shell quantum dots: A single-particle fluorescence study

Heyes, Colin D.; Kobitski, Andrei Yu; Breus, Vladimir V.; Nienhaus, G. Ulrich

doi:10.1103/physrevb.75.125431

Cited by 85 publications

(125 citation statements)

References 51 publications

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“…Studies dedicated to the influence of the shell thickness on the blinking statistics are few. The CdSe/ZnS blinking statistics as a function of ZnS thicknesses has been studied [26], but no correlation between the shell thickness and the blinking statistics was found. The difficulty with the CdSe/ZnS system is the large lattice mismatch between the core and the shell (>10%).…”

Section: Discussionmentioning

confidence: 98%

Toward non-blinking quantum dots: the effect of thick shell

Mahler¹,

Spinicelli

Quélin

et al. 2009

SPIE Proceedings

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Fluorescence spectroscopy studies have shown that, at a single molecule level, fluorophore emission intensity fluctuates between bright and dark states. These fluctuations, known as blinking, limit the use of fluorophores in single molecule experiments. Statistical analysis of these intensity fluctuations has demonstrated that the dark states duration exhibits a universal heavy-tailed power law distribution in organic as well as inorganic fluorophores. However, the precise reasons underlying the blinking of single fluorophores are still matter of debate and whether it can be suppressed is not clear. Here we have synthesized CdSe/CdS core/shell quantum dots (QDs) with thick crystalline shells, which do not blink at low frame rate and established a direct correlation between shell thickness and blinking occurrences. Single fluorophore blinking and blinking statistics are thus not as universal as thought so far. We anticipate our results to help better understand the physicochemistry of single fluorophore emission and rationalize the design of other fluorophores that do not blink. The materials presented here should readily find interesting applications in biology for single molecule tracking and in photonics as robust and continuous photon emitter.

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Section: Discussionmentioning

confidence: 98%

Toward non-blinking quantum dots: the effect of thick shell

Mahler¹,

Spinicelli

Quélin

et al. 2009

SPIE Proceedings

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“…Single step photobleaching A square region of 3×3 pixels around the center of each spot was chosen to extract intensitytime traces using custom written MatLab software 43 . Background was subtracted locally by considering the average intensity of a 2X2 pixel region surrounding the molecule of interest.…”

Section: Discussionmentioning

confidence: 99%

Single-molecule evaluation of fluorescent protein photoactivation efficiency using an in vivo nanotemplate

et al. 2014

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Photoswitchable fluorescent probes are central to localization-based super-resolution microscopy. Among these probes, fluorescent proteins are appealing because they are genetically encoded. Moreover, the ability to achieve a one to one labeling ratio between the fluorescent protein and the protein of interest makes them attractive for quantitative single molecule counting. The percentage of fluorescent protein that is photoactivated into a fluorescently detectable form (i.e. photoactivation efficiency) plays a critical role in properly interpreting the quantitative information. It is important to characterize the photoactivation efficiency at the single molecule level to replicate the conditions used in super-resolution imaging. Here, we used the human Glycine receptor expressed in Xenopus oocytes and stepwise photobleaching or single molecule counting-PALM to determine the percentage of photoactivated fluorescent protein for mEos2, mEos3.1, mEos3.2, Dendra2, mClavGR2, mMaple, PA-GFP and PA-mCherry. This analysis provides important information that must be considered when using these fluorescent proteins in quantitative super-resolution microscopy.

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“…Additionally, the shell thickness and chemical composition of core-shell QDs have been shown to be important parameters that affect the optical properties. 33–36 …”

mentioning

confidence: 99%

Probing the “Dark” Fraction of Core–Shell Quantum Dots by Ensemble and Single Particle pH-Dependent Spectroscopy

et al. 2011

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The optical properties of core-shell CdSe-ZnS quantum dots (QDs) are characterized by complex photophysics leading to difficulties in interpreting quantitative measurements based on QD emission. By comparing the pH dependence of fluorescence of single QDs to that of an ensemble, we have been able to propose a molecular scale model of how QD surface chemical and physical processes are affected by protons and oxygen. We show that the connection between the ensemble fluorescence intensity and the single QD fluorescence properties such as dark fraction, blinking, particle brightness and a multi-exponential fluorescence lifetime decay is not trivial. The ensemble fluorescence intensity is more weakly dependent on pH than the single particle fluorescence which, together with fluorescence lifetime analysis, provided evidence that the dark fraction of QDs emits photons with low quantum efficiency and long lifetime. We uncovered two surface-dependent mechanisms that affected the fluorescence emission: an immediate physical effect of charges surrounding the QD and an irreversible chemical effect from reaction of the H+ and O2 with the QD shell surface. These results will have important implications for those using QD-based fluorescence lifetime imaging as well as for proper implementation of these probes for quantitative cellular imaging applications.

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Effect of the shell on the blinking statistics of core-shell quantum dots: A single-particle fluorescence study

Cited by 85 publications

References 51 publications

Toward non-blinking quantum dots: the effect of thick shell

Toward non-blinking quantum dots: the effect of thick shell

Single-molecule evaluation of fluorescent protein photoactivation efficiency using an in vivo nanotemplate

Probing the “Dark” Fraction of Core–Shell Quantum Dots by Ensemble and Single Particle pH-Dependent Spectroscopy

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