title: Silver island film substrates for ultrasensitive fluorescence detection of (bio)molecules.
abstract: A silver island film (SIF) substrate was used to demonstrate that Metal-Enhanced Fluorescence (MEF) is a powerful tool to enable detection of emission from (bio)molecules at very low concentrations. The experiments were carried out with the Fenna-Matthews-Olson (FMO) pigment-protein complex from the photosynthetic green sulfur bacterium Chlorobaculum tepidum. FMO was diluted to a level, at which no emission was detectable on a glass substrate. In contrast, the fluorescence of FMO was readily observed on the SIF substrate, even though the emission wavelength of FMO is displaced by over 300 nm from the maximum of the plasmon resonance of the SIF layer. Estimated enhancements of the fluorescence intensity of FMO on SIF are about 40-fold. The enhancement factor correlates with the improvement of the signal-to-noise ratio for FMO emission on SIF substrates.
authors.affiliation: Faculty of Physics, Astronomy and Informatics, Institute of Physics, Nicolaus Copernicus University, ul. Grudziadzka 5, 87-100, Torun, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Szalkowski
authors.affiliation: Institute of Molecular, Cell & Systems Biology, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, Scotland, UK.
authors.forename: Khuram U
authors.initials: KU
authors.lastname: Ashraf
authors.affiliation: Institute of Molecular, Cell & Systems Biology, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, Scotland, UK.
authors.forename: Heiko
authors.initials: H
authors.lastname: Lokstein
authors.affiliation: Faculty of Physics, Astronomy and Informatics, Institute of Physics, Nicolaus Copernicus University, ul. Grudziadzka 5, 87-100, Torun, Poland. mackowski@fizyka.umk.pl.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Mackowski
authors.affiliation: Institute of Molecular, Cell & Systems Biology, Glasgow Biomedical Research Centre, University of Glasgow, 120 University Place, Glasgow, G12 8TA, Scotland, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cogdell
authors.affiliation: Faculty of Physics, Astronomy and Informatics, Institute of Physics, Nicolaus Copernicus University, ul. Grudziadzka 5, 87-100, Torun, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Kowalska
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D005453:Fluorescence; D005898:Glass; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D012834:Silver; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; C086320:FMO bacteriochlorophyll protein, Bacteria; D045342:Light-Harvesting Protein Complexes; D012834:Silver
keywords: Fenna−Matthews−Olson complex; Fluorescence; Metal-enhanced fluorescence; Plasmon; Signal-to-noise ratio; Silver island film