摘要：

Two-photon active probe to label apoptotic cells plays a significant role in biological systems. However, discrimination of live/apoptotic cells at subcellular level under microscopy remains unachieved. Here, three novel Zn­(II) terpyridine-based nitrate complexes (<bold>C1</bold>–<bold>C3</bold>) containing different pull/push units were designed. The structures of the ligands and their corresponding Zn­(II) complexes were confirmed by single-crystal X-ray diffraction analysis. On the basis of the comprehensive comparison, <bold>C3</bold> had a suitable two-photon absorption cross section in the near-infrared wavelength and good biocompatibility. Under two-photon confocal microscopy and transmission electron microscopy, it is found that <bold>C3</bold> could target mitochondria in living cells but immigrate into the nucleolus during the apoptotic process. This dual-functional probe (<bold>C3</bold>) not only offers a valuable image tool but also acts as an indicator for cell mortality at subcellular level in a real-time manner. Zn­(II) terpyridine-based nitrate complex <bold>C3</bold> had a moderate two-photon absorption cross-section in the NIR region and good biocompatibility toward mitochondria, which was not unexpected, but immigrated to the nucleolus in apoptotic cells due to the loss of mitochondrial electrochemical potential and increased nuclear membrane permeability. Importantly, it was the first time <bold>C3</bold> offered a tool to investigate their dynamic change during apoptotic process, with high biocompability and photon-stability.

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