title: Two-photon optical properties of near-infrared dyes at 1.55 μm excitation.
abstract: Two-photon (2P) optical properties of cyanine dyes were evaluated using a 2P fluorescence spectrophotometer with 1.55 μm excitation. We report the 2P characteristics of common NIR polymethine dyes, including their 2P action cross sections and the 2P excited fluorescence lifetime. One of the dyes, DTTC, showed the highest 2P action cross-section (∼103 ± 19 GM) and relatively high 2P excited fluorescence lifetime and can be used as a scaffold for the synthesis of 2P molecular imaging probes. The 2P action cross-section of DTTC and the lifetime were also highly sensitive to the solvent polarity, providing other additional parameters for its use in optical imaging and the mechanism for probing environmental factors. Overall, this study demonstrated the quantitative measurement of 2P properties of NIR dyes and established the foundation for designing molecular probes for 2P imaging applications in the NIR region.
authors.affiliation: Department of Radiology, Washington University, St. Louis, Missouri 63110, USA. berezinm@mir.wustl.edu
authors.forename: Mikhail Y
authors.initials: MY
authors.lastname: Berezin
authors.forename: Chun
authors.initials: C
authors.lastname: Zhan
authors.forename: Hyeran
authors.initials: H
authors.lastname: Lee
authors.forename: Chulmin
authors.initials: C
authors.lastname: Joo
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Akers
authors.forename: Siavash
authors.initials: S
authors.lastname: Yazdanfar
authors.forename: Samuel
authors.initials: S
authors.lastname: Achilefu
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000737:chemistry*; D007668:Kidney / Q000033:anatomy & histology; D051379:Mice; D008856:Microscopy, Fluorescence; D017785:Photons; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D012997:Solvents