Dai Peiling, Luo Chenxiao, Xu Zhiqi, Sun Shuaishuai, Tian Yuyang, Zhang Kenneth Yin, Lo Kenneth Kam-Wing, Liu Shujuan, Huang Wei, Wang Huan, Zhao Qiang
State Key Laboratory of Flexible Electronics (LoFE) & Jiangsu Key Laboratory of Smart Biomaterials and Theranostic Technology, Institute of Advanced Materials (IAM) and College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts & Telecommunications, Nanjing, 210023, P.R. China.
State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center of Nanjing University, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China.
Angew Chem Int Ed Engl. 2025 Apr 22:e202504230. doi: 10.1002/anie.202504230.
Fluorogenic bioorthogonal probes are crucial tools in biomedical research, which enable non-invasive, wash-free imaging of specific biomolecules in living systems. Lifetime-responsive bioorthogonal probes represent another promising and attractive alternative, offering the potential for real-time, wash-free visualization of bioorthogonal labeling processes via photoluminescence lifetime imaging microscopy (PLIM). However, their widespread application is limited by the lack of suitable lifetime-responsive probes. Herein, a series of phosphorescent iridium(III) phenanthrolinedione complexes were reported. Intriguingly, upon bioorthogonal reaction with an α-angelica lactone derivative, the complexes exhibited remarkable emission responses in three distinct manners, which were found to correlate with the different emissive excited states of the complexes. Crucially, two of the complexes maintained similar emission intensity but exhibited significant emission lifetime elongation during labeling reactions, which facilitated simultaneous and discriminative visualization of the reacted and unreacted probes in cellular imaging without the need for washing steps. One of the complexes was used for organelle targeting and specific protein labeling through bioorthogonal reactions in living cells. The intracellular probe transportation and labeling dynamics were visualized and analyzed using PLIM. This work highlights the unique potential of lifetime-responsive iridium(III) complexes as powerful chemical tools for live-cell imaging and unveiling the spatiotemporal dynamics of biomolecules during bioorthogonal reactions.
荧光生物正交探针是生物医学研究中的关键工具，能够对活体细胞中的特定生物分子进行非侵入性、免洗成像。寿命响应型生物正交探针是另一种有前景且有吸引力的选择，它通过光致发光寿命成像显微镜（PLIM）为生物正交标记过程的实时、免洗可视化提供了可能。然而，由于缺乏合适的寿命响应型探针，它们的广泛应用受到了限制。在此，我们报道了一系列磷光铱（III）菲咯啉二酮配合物。有趣的是，在与α-当归内酯衍生物发生生物正交反应时，这些配合物呈现出三种不同的显著发射响应，这与配合物不同的发射激发态相关。至关重要的是，其中两种配合物在标记反应过程中保持相似的发射强度，但发射寿命显著延长，这有助于在细胞成像中同时区分已反应和未反应的探针，而无需洗涤步骤。其中一种配合物通过活细胞中的生物正交反应用于细胞器靶向和特定蛋白质标记。利用PLIM对细胞内探针的运输和标记动力学进行了可视化和分析。这项工作突出了寿命响应型铱（III）配合物作为用于活细胞成像和揭示生物正交反应过程中生物分子时空动态的强大化学工具的独特潜力。
