Origin of bimodal fluorescence enhancement factors of Chlorobaculum tepidum reaction centers on silver island films

FEBS Lett. 2016 Aug;590(16):2558-65. doi: 10.1002/1873-3468.12292. Epub 2016 Jul 26.

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.

Keywords: bacteriochlorophyll; excitation energy transfer; fluorescence; plasmonic enhancement; silver island film.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Chlorobi / chemistry*
  • Chlorobi / genetics
  • Chlorobi / metabolism
  • Cytoplasm / chemistry*
  • Cytoplasm / genetics
  • Energy Transfer / genetics
  • Fluorescence*
  • Light-Harvesting Protein Complexes / chemistry*
  • Light-Harvesting Protein Complexes / genetics
  • Spectrometry, Fluorescence

Substances

  • Bacterial Proteins
  • FMO bacteriochlorophyll protein, Bacteria
  • Light-Harvesting Protein Complexes