ANYL 265 |
| We employed the single molecule spectroscopy (SMS) method to investigate surface immobilized species to examine metal-fluorophore interactions. We observed fluorescence enhancements and lifetime reductions of Cy5 probe molecules at various distances from the deposited silver island film (SIF) surface at single molecule levels. The proximity of fluorophore molecules to the surface was controlled either by directly tethering single flurophore-labeled DNA to silver island films or constructing layers of biotinylated bovine serum albumin (BSA-biotin) and avidin, followed by binding of Cy5-labeled oligonucleotides to the top of a BSA-biotin layer structure. In addition, we studied the photophysical behavior of enhanced Förster Resonance Energy Transfer (FRET) near single metal nanoparticles. Donor-labeled oligonucleotide was chemically bound to a single silver particle and an acceptor-labeled oligonucleotide was hybridized. Single-molecule fluorescence measurements indicated that FRET was significantly enhanced, which resulted in increasing the transfer efficiency and lengthening the distance of energy transfer. These single-molecule studies illustrate the exclusive information that is otherwise hidden in ensemble measurements. The effects may also be used for increased delectability of single molecules bound to surfaces which contain metallic structures, for either biophysical studies or high sensitivity assays. |
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Analytical Approaches, Spectroscopy
8:30 AM-12:00 PM, Wednesday, 13 September 2006 Moscone Center -- Room 124, Oral
Division of Analytical Chemistry |