Plasmonic enhancement of single-molecule fluorescence near metal nanoparticles

ANYL 462

Yi Fu, yifu@cfs.umbi.umd.edu, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD 21201, Jian Zhang, jian@cfs.umbi.umd.edu, Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, and Joseph R. Lakowicz, lakowicz@cfs.umbi.umd.edu, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201.
We reported the study of the enhanced fluorescence of fluorophores bound to silver nanoparticles at the single-molecule level. Double-stranded DNA is used as a rigid spacer to control the distance between the fluorophore and the nanoparticle. We observed reduced blinking and enhanced photostability of fluorophores near silver nanoparticles. In addition, we found that on average Cy5 molecules bound to 50 nm metal nanoparticles are approximately 15-fold brighter than that of free dyes, and that single molecule lifetimes are shorter as compared to free fluorophores. The size effect of nanoparticles has also been investigated. The increased emission rate is primarily the result of local plasmon enhancement. These results demonstrate that the use of fluorophore-metal interactions can increase the brightness and photostability of fluorophores for single molecule detection
 

Analytical Approaches
1:30 PM-4:30 PM, Thursday, August 23, 2007 BCEC -- 104A, Oral

Division of Analytical Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007