title: Fluorescence enhancement using silver-gold nanocomposite substrates.
abstract: Metal-enhanced fluorescence (MEF) is a newly emerging phenomenon in which the near-field interactions of fluorophores with the plasmons in metallic nanostructures can lead to substantial fluorescence enhancements. In the present study, we have investigated the use of silver-gold nanocomposite (Ag-Au-NC) structures, prepared by the galvanic replacement reaction of silver with gold, as plasmonic substrates for MEF. We have observed significant enhancement in the fluorescence intensities and decrease in the fluorescence lifetimes of two commonly used dyes, ATTO655 and Cy5, using the fabricated Ag-Au-NC substrates. Interestingly, the fluorescence enhancement depends on the amount of residual silver present in the substrates after the galvanic replacement reaction. Our results show that the galvanic replacement reaction is a very facile and powerful route to prepare Ag-Au-NC substrates that can be suitable for various MEF based applications.
authors.affiliation: Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, MD 21201, USA.
authors.forename: Sharmistha Dutta
authors.initials: SD
authors.lastname: Choudhury
authors.forename: Ramachandram
authors.initials: R
authors.lastname: Badugu
authors.forename: Krishanu
authors.initials: K
authors.lastname: Ray
authors.forename: Prasanna Sai
authors.initials: PS
authors.lastname: Vanam
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Lakowicz
keywords: Silver-gold nanocomposites; galvanic replacement; metal enhanced fluorescence; plasmon controlled fluorescence; plasmonics
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