Lipid droplets (LDs) are crucial organelles that play important roles in various physiological and pathological processes. The LD–mitochondria interplay is pivotal for cellular energy metabolism and lipid homeostasis. It is thus vital to develop high-performance LD–mitochondria dual imaging probes for studying their biological functions. Herein, we reported a new class of conditionally activated fluorogenic probes based on the conjugation of chromone and tetrazine. These probes could be either photoactivated to generate photostable and solvatochromic photoproducts for visualizing LDs and real-time, in situ monitoring of ferroptosis-induced LD dynamics with a high level of spatiotemporal control or bioorthogonally activated for mitochondria-specific imaging based on a pre-targeted approach. Most importantly, this strategy was successfully applied to label LDs and mitochondria simultaneously and realized two-color imaging in the lambda mode, which showed the great potential of using fluorescence imaging to explore the functions of LDs and related organelles.

中文翻译：

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四嗪衍生的色酮作为条件激活的溶剂化显色荧光探针，用于脂滴和线粒体的双重成像

脂滴（LD）是重要的细胞器，在各种生理和病理过程中发挥重要作用。 LD-线粒体相互作用对于细胞能量代谢和脂质稳态至关重要。因此，开发高性能LD-线粒体双成像探针对于研究其生物学功能至关重要。在此，我们报道了一类基于色酮和四嗪缀合的新型条件激活荧光探针。这些探针可以被光激活以产生光稳定和溶剂致变色的光产物，用于可视化 LD，并通过高水平的时空控制实时、原位监测铁死亡诱导的 LD 动力学，或者生物正交激活以基于预靶向的线粒体特异性成像方法。最重要的是，该策略成功应用于同时标记LD和线粒体，并实现了lambda模式的双色成像，这显示了利用荧光成像探索LD和相关细胞器功能的巨大潜力。