Blinking and nonradiant dark fraction of water-soluble quantum dots in aqueous solution.

ABSTRACT: Water-soluble quantum dots (qdots) are now being used in life sciences research to take advantage of their bright, easily excited fluorescence and high photostability. Although the frequent erratic blinking and substantial dark (never radiant) fractions that occur in all available qdots may interfere with many applications, these properties of individual particles in biological environments had not been fully evaluated. By labeling Qdot-streptavidin with organic dyes, we were able to distinguish individual dark and bright qdots and to observe blinking events as qdots freely diffused in aqueous solution. Bright fractions were measured by confocal fluorescence coincidence analysis (CFCA) and two-photon cross-correlation fluorescence correlation spectroscopy (FCS). The observed bright fractio

SUBMITTER: Yao J 

PROVIDER: S-EPMC1242317 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature