Biological Oxygen Sensing via Two-Photon Absorption by an Ir(III) Complex using a Femtosecond Fiber Laser
H. Moritomo, A. Fujii, Y. Suzuki, T. Yoshihara, S. Tobita, J. Kawamata
Jpn. J. Appl. Phys., 2016, 55, 092401
DOI: 10.7567/JJAP.55.092401

Abstruct: Near-infrared two-photon absorption of the phosphorescent Ir(III) complex (2,4-pentanedionato-κO 2,κO 4)bis[2-(6-phenanthridinyl-κN)benzo[b]thien-3-yl-κC]iridium (BTPHSA) was characterized. It exhibited a 800–1200 nm two-photon absorption band, and thus could be electronically excited by 1030-nm femtosecond Ti:sapphire and Yb-doped fiber lasers. By using BTPHSA, oxygen concentrations in human embryonic kidney 293 (HEK293) cells were imaged. These results demonstrate two-photon oxygen sensing of live tissues via easily operable excitation sources.