title: Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf.
abstract: Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.
authors: The City College of the City University of New York, Department of Biomedical Engineering, 160 Convent Avenue, New York 10031bThe City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical E.
authors: Lingyan
authors: L
authors: Shi
authors: The City College of the City University of New York, Department of Biology, 160 Convent Avenue, New York 10031.
authors: Adrián
authors: A
authors: Rodríguez-Contreras
authors: The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031.
authors: Yury
authors: Y
authors: Budansky
authors: The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031.
authors: Yang
authors: Y
authors: Pu
authors: The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031.
authors: Thien An
authors: TA
authors: Nguyen
authors: The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031.
authors: Robert R
authors: RR
authors: Alfano
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000473:pathology*; D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D005456:Fluorescent Dyes / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D008856:Microscopy, Fluorescence; D017785:Photons; D018515:Plant Leaves / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D012542:Scattering, Radiation; D018724:Spinacia oleracea / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D002734:Chlorophyll; D000077194:Chlorophyll A