title: Origin of bimodal fluorescence enhancement factors of Chlorobaculum tepidum reaction centers on silver island films.
abstract: We focus on the spectral dependence of plasmon-induced enhancement of fluorescence of Chlorobaculum tepidum reaction centers. When deposited on silver island film, they exhibit up to a 60-fold increase in fluorescence. The dependence of enhancement factors on the excitation wavelength is not correlated with the absorption spectrum of the plasmonic structure. In particular, the presence of one (or multiple) trimers of the Fenna-Matthews-Olson (FMO) protein reveals itself in bimodal distribution of enhancement factors for the excitation at 589 nm, the wavelength corresponding to bacteriochlorophyll absorption of FMO and the core of the RC. We conclude that the structure of multichromophoric complexes can substantially affect the impact of plasmonic excitations, which is important in the context of assembling functional biohybrid systems.
authors.affiliation: Optics of Hybrid Nanostructures Group, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Maćkowski
authors.affiliation: Optics of Hybrid Nanostructures Group, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
authors.forename: Nikodem
authors.initials: N
authors.lastname: Czechowski
authors.affiliation: Institute of Molecular, Cell & Systems Biology, Glasgow Biomedical Research Centre, University of Glasgow, UK.
authors.forename: Khuram U
authors.initials: KU
authors.lastname: Ashraf
authors.affiliation: Optics of Hybrid Nanostructures Group, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, 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, UK.
authors.forename: Heiko
authors.initials: H
authors.lastname: Lokstein
authors.affiliation: Institute of Molecular, Cell & Systems Biology, Glasgow Biomedical Research Centre, University of Glasgow, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cogdell
authors.affiliation: Optics of Hybrid Nanostructures Group, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Kowalska
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D019414:Chlorobi / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry* / Q000235:genetics; D004735:Energy Transfer / Q000235:genetics; D005453:Fluorescence; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000235:genetics; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; C086320:FMO bacteriochlorophyll protein, Bacteria; D045342:Light-Harvesting Protein Complexes
keywords: bacteriochlorophyll; excitation energy transfer; fluorescence; plasmonic enhancement; silver island film