| Abstract
| - Methods that increase the total emission per fluorophorewould provide increased sensitivity and a wider dynamicrange for chemical analysis, medical diagnostics, and invivo molecular imaging. The use of fluorophore−metalinteractions has the potential to dramatically increase thedetectability of single fluorophores for bioanalytical monitoring. The fabrication and single-molecule analysis offluorophore-labeled DNA molecules tethered to silverisland films are described in this article. The single-molecule spectroscopic method reveals some insightfulinformation on the behaviors of single molecules, ratherthan an ensemble of molecules. Analysis of fluorescenceimages, intensity profiles, total emitted photons, andlifetime distributions reveals some of sample heterogeneities. Investigations of time-dependent emission characteristics of single molecules indicate that the totalnumber of emitted photons on the silvered surface is morethan 10 times greater than on free labeled DNA moleculeson a glass substrate. In addition, time-correlated single-photon counting results reveal the reduced lifetimes ofsingle molecules tethered to silver island films.
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