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Saturation of two-photon excitation provides insight into the effects of a quantum dot blinking suppressant: A fluorescence correlation spectroscopy study

Heuff, Romey F. and Marrocco, Michele and Cramb, David T. (2007) Saturation of two-photon excitation provides insight into the effects of a quantum dot blinking suppressant: A fluorescence correlation spectroscopy study. JOURNAL OF PHYSICAL CHEMISTRY C, 111 (51). pp. 18942-18949.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/jp709604

Abstract

Quantum dots are now extensively used as luminescent tags for biological and chemical applications; however, their propensity to display intermittent luminescence (aka blinking) has limited their use in quantitative assays. Various surface active redox agents, such as ss-mercaptoethanol, have been posited as antiblinking agents to help mitigate this challenge. We have examined the effect of ss-mercaptoethanol on the luminescence intermittency of CdSe/ZnS quantum dots using fluorescence correlation spectroscopy. We find that ss-mercaptoethanol lowers the quantum dot brightness and therefore lowers the probability of observing blinking but does not otherwise inhibit intermittent luminescence. Based on changes in fluorescence correlation data and excited-state lifetimes, we propose that the partitioning of ss-mercaptoethanol onto the quantum dot surfaces increases nonradiative de-excitation rates. This behavior appears to be independent of the quantum dot surface passivation layer or the solution contents.

Item Type:Article
Subjects:Material Science > Functional and hybrid materials
Analytical Science > Microscopy and probe methods
ID Code:1852
Deposited By:Farnush Anwar
Deposited On:16 Dec 2008 14:36
Last Modified:12 Jan 2009 12:05

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