One- and two-photon induced fluorescence of Pacific Blue-labeled human serum albumin deposited on different core size silver colloids

Biopolymers. 2006 Mar;81(4):249-55. doi: 10.1002/bip.20407.


We studied one- and two-photon induced fluorescence of Pacific Blue (PB)-labeled human serum albumin (HSA) in the presence of different size silver colloids. The PB fluorescence emission intensity was observed with small (30-40 nm) and large (about 120 nm) colloids and compared with PB emission in absence of colloids. For the system with a small core size colloids we did not detect any fluorescence enhancement with one-photon excitation and the enhancement observed with two-photon excitation was about 2.5-fold. In contrast, for large silver colloids we observed about a 2-fold increase in PB fluorescence brightness for one-photon excitation, and the enhancement with two-photon excitation excided 13-folds. Much stronger increases in brightness observed with two-photon excitation, compared to one-photon excitation, indicate a dominant role of enhanced local field in fluorescence enhancement on silver colloids in solutions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colloids / chemistry*
  • Fluorescent Dyes / chemistry*
  • Humans
  • Microscopy, Fluorescence, Multiphoton / methods*
  • Particle Size
  • Photons
  • Serum Albumin / chemistry*
  • Silver / chemistry*
  • Spectrometry, Fluorescence
  • Succinimides / chemistry*


  • Colloids
  • Fluorescent Dyes
  • Pacific Blue succinimidyl ester
  • Serum Albumin
  • Succinimides
  • Silver