A Bioaccumulative Cyclometalated Platinum(II) Complex with Two-Photon-Induced Emission for Live Cell Imaging

Chi Kin Koo, Ka Leung Wong, Cornelia Wing Yin Man, Yun Wah Lam, Leo King Yan So, Hoi Lam Tam, Sai Wah Tsao, Kok Wai Cheah, Kai Chung Lau, Yang Yi Yang, Jin Can Chen, Michael Hon Wah Lam

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The cyclometalated platinum(II) complex [Pt(L)Cl], where HL is a new cyclometalating ligand 2-phenyl-6-(1H-pyrazol-3-yl)pyridine containing C phenyl, Npyridyl, and Npyrazolyl donor moieties, was found to possess two-photon-induced luminescent properties. The two-photon-absorption cross section of the complex in N,N-dimethylformamide at room temperature was measured to be 20.8 GM. Upon two-photon excitation at 730 nm from a Ti:sapphire laser, bright-green emission was observed. Besides its two-photon-induced luminescent properties, [Pt(L)Cl] was able to be rapidly accumulated in live HeLa and NIH3T3 cells. The two-photon-induced luminescence of the complex was retained after live cell internalization and can be observed by two-photon confocal microscopy. Its bioaccumulation properties enabled time-lapse imaging of the internalization process of the dye into living cells. Cytotoxicity of [Pt(L)Cl] to both tested cell lines was low, according to MTT assays, even at loadings as high as 20 times the dose concentration for imaging for 6 h.

Original languageEnglish
Pages (from-to)872-878
Number of pages7
JournalInorganic Chemistry
Issue number3
Early online date7 Jan 2009
Publication statusPublished - 2 Feb 2009
Externally publishedYes

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