Localized surface plasmon resonance fluorescence enhancement

The optimal enhancement effect is observed when the localized surface plasmon resonance is tuned to the emission wavelength of a locally situated fluorophore [86]. This is consistent with the model suggesting a greatly increased efficiency for energy transfer from fluorophores to surface plasmons [78]. Since resonance energy transfer is involved, the important factors affecting the intensity of fluorescence emission must also be the orientation of the dye dipole moments relative to the... 

Metal nanoparticles have attracted considerable interest due to their properties and applications related to size effects, which can be appropriately studied in the framework of nanophotonics [1]. Metal nanoparticles such as silver, gold and copper can scatter light elastically with remarkable efficiency because of a collective resonance of the conduction electrons in the metal (i.e., the Dipole Plasmon Resonance or Localized Surface Plasmon Resonance). Plasmonics is quickly becoming a dominant science-based technology for the twenty-first century, with enormous potential in the fields of optical computing, novel optical devices, and more recently, biological and medical research [2]. In particular, silver nanoparticles have attracted particular interest due to their applications in fluorescence enhancement [3-5]. 

Nanoporous platforms recently have found utility in the fields of plasmonics and optical detection. Nanoporous gold fllms and metallic-coated nanopores - have been applied to techniques like surface-plasmon resonance (SPR) and surface-enhanced Raman spectroscopy (SERS). Additionally, nanoporous metal has been demonstrated to enhance single-molecule fluorescence intensity of immobilized fluorophores due to the enhanced localized plasmon field present within the nanopores. Optically transparent alumina membranes have been developed and found utility as optical biosensors. Additionally, nanoporous gold has been demonstrated to optically detect Hg + ions at concentrations smaller than parts per trillion. A fiber-optic ultrasound generator has been developed from the excitation of gold nanopores with a nanosecond laser. ... 

The electromagnetic nature of surface-enhanced Raman scattering (SERS) and plasmon-enhanced fluorescence (PEF) involves resonant excitations of localized plasmons (LPs) in the near-field of nanosized noble metal particles or films, coupling them with surrounding scatterers and detection of their secondary emission in the far field. Employment of these plasmonic phenomena are proposed, for example, as a new approach to increase brightness of heavily labeled macromolecules [1]. 

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