Two-photon excited surface plasmon enhanced energy transfer between DAPI and gold nanoparticles: opportunities in intra-cellular imaging and sensing

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We have demonstrated energy transfer between 4'-6-Diamidino-2-phenylindole (DAPI), a commonly used DNA label, and gold nanoparticles under two-photon excitation in solution using fluorescence lifetime imaging microscopy (FLIM). With comparable size and concentration, gold nanorods (GNRs) are shown to provide more efficient energy transfer than gold nanospheres (GNSs). We attribute this transfer enhancement effect to the longitudinal surface plasmon mode of GNRs overlapping with the excitation wavelength. Energy transfer under two-photon excitation between GNRs and DAPI has also been observed in cell culture and found to be in accord with the solution phase results.

Original languageEnglish
Article number103701
Pages (from-to)-
Number of pages3
JournalApplied Physics Letters
Issue number10
Publication statusPublished - 5 Sep 2011


  • biomedical optical imaging
  • cellular biophysics
  • excited states
  • fluorescence
  • gold
  • nanomedicine
  • nanoparticles
  • nanorods
  • nanosensors
  • surface plasmon resonance
  • two-photon processes
  • resonance
  • TIC - Bionanotechnology

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