title: Oxygen microscopy by two-photon-excited phosphorescence.
abstract: High-resolution images of oxygen distributions in microheterogeneous samples are obtained by two-photon laser scanning microscopy (2P LSM), using a newly developed dendritic nanoprobe with internally enhanced two-photon absorption (2PA) cross-section. In this probe, energy is harvested by a 2PA antenna, which passes excitation onto a phosphorescent metalloporphyrin via intramolecular energy transfer. The 2P LSM allows sectioning of oxygen gradients with near diffraction-limited resolution, and lifetime-based acquisition eliminates dependence on the local probe concentration. The technique is validated on objects with a priori known oxygen distributions and applied to imaging of pO(2) in cells.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvannia, Philadelphia, PA 19104-6059, USA.
authors.forename: Olga S
authors.initials: OS
authors.lastname: Finikova
authors.forename: Artem Y
authors.initials: AY
authors.lastname: Lebedev
authors.forename: Alexey
authors.initials: A
authors.lastname: Aprelev
authors.forename: Thomas
authors.initials: T
authors.lastname: Troxler
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Carmen
authors.initials: C
authors.lastname: Garnacho
authors.forename: Silvia
authors.initials: S
authors.lastname: Muro
authors.forename: Robin M
authors.initials: RM
authors.lastname: Hochstrasser
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Vinogradov
mesh_terms: D002478:Cells, Cultured; D042783:Endothelial Cells; D006801:Humans; D008163:Luminescent Measurements; D008853:Microscopy / Q000379:methods*; D015394:Molecular Structure; D049329:Nanostructures; D010100:Oxygen / Q000737:chemistry*; D010777:Photochemistry; D017785:Photons
chemical_list: D010100:Oxygen