title: Wide-field time-correlated single-photon counting (TCSPC) lifetime microscopy with microsecond time resolution.
abstract: A 1 MHz frame rate complementary metal-oxide semiconductor (CMOS) camera was used in combination with an image intensifier for wide-field time-correlated single-photon counting (TCSPC) imaging. The system combines an ultrafast frame rate with single-photon sensitivity and was employed on a fluorescence microscope to image decays of ruthenium compound Ru(dpp) with lifetimes from around 1 to 5 μs. A submicrowatt excitation power over the whole field of view is sufficient for this approach, and compatibility with live-cell imaging was demonstrated by imaging europium-containing beads with a lifetime of 570 μs in living HeLa cells. A standard two-photon excitation scanning fluorescence lifetime imaging (FLIM) system was used to independently verify the lifetime for the europium beads. This approach brings together advantageous features for time-resolved live-cell imaging such as low excitation intensity, single-photon sensitivity, ultrafast camera frame rates, and short acquisition times.
authors.forename: Liisa M
authors.initials: LM
authors.lastname: Hirvonen
authors.forename: Frederic
authors.initials: F
authors.lastname: Festy
authors.forename: Klaus
authors.initials: K
authors.lastname: Suhling
mesh_terms: D005063:Europium / Q000737:chemistry / Q000378:metabolism; D005990:Glycerol / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008163:Luminescent Measurements; D008853:Microscopy / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry; D017785:Photons; D012666:Semiconductors; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D010618:Phenanthrolines; D014867:Water; D005063:Europium; C041132:tris(4,7-diphenyl-1,10-phenanthroline)ruthenium (II); D005990:Glycerol