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Confocal, three-dimensional tracking of individual quantum dots in high-background environments.

ABSTRACT: We demonstrate a custom confocal fluorescence-microscope that is capable of tracking individual quantum dots undergoing three-dimensional Brownian motion (diffusion coefficient approximately 0.5 microm(2)/s) in environments with a signal-to-background ratio as low as 2:1, significantly worse than observed in a typical cellular environment. By utilizing a pulsed excitation source and time-correlated single photon counting, the time-resolved photon stream can be used to determine changes in the emission lifetime as a function of position and positively identify single quantum dots via photon-pair correlations. These results indicate that this microscope will be capable of following protein and RNA transport throughout the full three-dimensional volume of a live cell for durations up to 15 s.

SUBMITTER: Wells NP

PROVIDER: S-EPMC4337952 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature

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Confocal, three-dimensional tracking of individual quantum dots in high-background environments.

Wells Nathan P NP Lessard Guillaume A GA Werner James H JH

Analytical chemistry 20081201 24

We demonstrate a custom confocal fluorescence-microscope that is capable of tracking individual quantum dots undergoing three-dimensional Brownian motion (diffusion coefficient approximately 0.5 microm(2)/s) in environments with a signal-to-background ratio as low as 2:1, significantly worse than observed in a typical cellular environment. By utilizing a pulsed excitation source and time-correlated single photon counting, the time-resolved photon stream can be used to determine changes in the em ...[more]

PMID: 19072277

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