title: One- and two-photon induced fluorescence of Pacific Blue-labeled human serum albumin deposited on different core size silver colloids.
abstract: 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.
authors.affiliation: Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Lukomska
authors.forename: Ignacy
authors.initials: I
authors.lastname: Gryczynski
authors.forename: Joanna
authors.initials: J
authors.lastname: Malicka
authors.forename: Slawomir
authors.initials: S
authors.lastname: Makowiec
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Lakowicz
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Gryczynski
mesh_terms: D003102:Colloids / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D010316:Particle Size; D017785:Photons; D012709:Serum Albumin / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013388:Succinimides / Q000737:chemistry*
chemical_list: D003102:Colloids; D005456:Fluorescent Dyes; C510619:Pacific Blue succinimidyl ester; D012709:Serum Albumin; D013388:Succinimides; D012834:Silver