Nonlinear excitation of tryptophan emission enhanced by silver nanoparticles

Diego Rativa, Anderson S L Gomes, Sebastian Wachsmann-Hogiu, Daniel L. Farkas, Renato E. De Araujo

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


We measured and analyzed the behavior of the fluorescence of tryptophan water solutions with and without silver nanoparticles, excited by one, two and three photon processes. Two different colloids with silver nanoparticles with distinct diameters (0.65 nm and 9 nm) were used in the experiments. Fluorescence quenching was observed with one and two photon excitation. However, upon three-photon excitation, significant fluorescence enhancement was observed in the colloid. In this case excitation of the amino acid is assisted by the nonlinear absorption of infrared light by the silver nanoparticles. In this paper we are proposing a new way to explore metallic nanoparticles to enhance autofluorescence of biomolecules.

Original languageEnglish (US)
Pages (from-to)1151-1155
Number of pages5
JournalJournal of Fluorescence
Issue number6
StatePublished - Nov 2008


  • Autofluorescence
  • Metallic nanoparticles
  • Nonlinear excitation
  • Tryptophan

ASJC Scopus subject areas

  • Spectroscopy
  • Biochemistry
  • Clinical Biochemistry


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