title: Picosecond-pulse-induced two-photon fluorescence enhancement in biological material by application of grating waveguide structures.
abstract: We report enhancement of two-photon fluorescence (TPF) excitation in fluorescent dyes and fluorescently labeled biomolecules by exploiting the optical properties of double grating waveguide structures (DGWSs). Picosecond laser pulses generate a large evanescent field based on the guided mode phenomenon in the resonant DGWSs, which induces strong TPF signals from fluorescent dyes at the waveguide surface. By recording enhanced TPF signals of Rhodamine B and Lucifer Yellow under resonance conditions, a detection sensitivity of concentrations of approximately one dye molecule per 0.1 microm2 was achieved. For the first time to our knowledge, enhanced TPF signals of a Lucifer Yellow-labeled biomolecule (human self-peptide) in an aqueous environment are demonstrated. These results strongly encourage the use of DGWSs as enhancement platforms in modern biophysics and biotechnology for investigations of biological membranes and cells.
authors.affiliation: Laser-Laboratorium Göttingen e. V., Hans-Adolf-Krebs-Weg 1, D-37077 Göttingen, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Selle
authors.forename: Christoph
authors.initials: C
authors.lastname: Kappel
authors.forename: Mark Andreas
authors.initials: MA
authors.lastname: Bader
authors.forename: Gerd
authors.initials: G
authors.lastname: Marowsky
authors.forename: Kathrin
authors.initials: K
authors.lastname: Winkler
authors.forename: Ulrike
authors.initials: U
authors.lastname: Alexiev
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation* / Q000379:methods; D010455:Peptides / Q000032:analysis*; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods
chemical_list: D010455:Peptides