title: Largely enhanced single-molecule fluorescence in plasmonic nanogaps formed by hybrid silver nanostructures.
abstract: It has been suggested that narrow gaps between metallic nanostructures can be practical for producing large field enhancement. We design a hybrid silver nanostructure geometry in which fluorescent emitters are sandwiched between silver nanoparticles and silver island film (SIF). A desired number of polyelectrolyte layers are deposited on the SIF surface before the self-assembly of a second silver nanoparticle layer. Layer-by-layer configuration provides a well-defined dye position. It allows us to study the photophyical behaviors of fluorophores in the resulting gap at the single molecule level. The enhancement factor of a fluorophore located in the gap is much higher than those on silver surfaces alone and on glass. These effects may be used for increased detectability of single molecules bound to surfaces which contain metallic structures for either biophysical studies or high sensitivity assays.
authors: Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 W. Lombard Street, Baltimore, Maryland 21201, USA. yfu@umaryland.edu
authors: Yi
authors: Y
authors: Fu
authors: Jian
authors: J
authors: Zhang
authors: Joseph R
authors: JR
authors: Lakowicz
mesh_terms: D004573:Electrolytes / Q000737:chemistry; D005453:Fluorescence; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D053770:Nanowires / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004573:Electrolytes; D011108:Polymers; D012834:Silver
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