Cuproptosis tracker: Visualizing organelle dynamics with a dual-targeted fluorescent probe

Cuproptosis often interacts with mitochondrial (Mito) dysfunction and lipid droplets (LDs) metabolism disturbances, thus resulting in programmed cell death, whereas their dynamic interaction lacks a rational analyzing tool. Herein, we show a Mito-LDs dual-targeted fluorescent reporter (MLR) for tracking the Mito-LDs interaction during cuproptosis by dynamic monitoring of intracellular sulfur dioxide (SO 2 ) dynamics. MLR integrates a coumarin-derived SO 2 -responsive core linked via piperazine to a benzopyronium Mitol anchor, enabling one-step synthesis with exceptional sensitivity (0.34 μM) and rapid response (<10 s). Live-cell imaging demonstrated MLR’s SO 2 -triggered translocation from Mito to LDs during cuproptosis, directly visualizing inter-organelle communication. Dual fluorescence channel imaging associated SO 2 fluctuations with Mito-LDs targeting, revealing the interaction between LDs-Mito during Cu 2+ and elesclomol induced apoptosis. In addition to imaging, MLR-based test strips and hydrogels can achieve rapid (< 1 min) on-site SO 2 detection. As a dual-organelle tracer for cuproptosis, MLR overcomes single-target probe limitations, offering a transformative platform to analyze spatiotemporal organelle dynamics for advancing diagnostic tools development. • Dual-organelle (Mito-LDs) tracking via amphiphilic ions, enabling SO 2 -mediated fluorescence tracing during cuproptosis with low LOD (0.34 μM) and rapid response (<10 s). • Achieving SO 2 specific detection by Michael addition reaction, combined with dual channel ratio imaging (I 575 /I 637 = 23.8 times) to quantitatively reveal the SO2 metabolic law in cuproptosis. • Rapid (<1 min) on-site SO 2 detection, extending to real-time tracking of copper toxicity in zebrafish, bridging basic research with clinical/environmental applications.