Near-infrared fluorescent probe for simultaneous monitoring of HClO and viscosity during Cuproptosis.

Cuproptosis is a newly uncovered copper-dependent cell death pathway closely tied to intracellular redox imbalance and reshaping of subcellular microenvironments. As a core endogenous reactive oxygen species, hypochlorous acid (HClO) dominates oxidative stress cascades triggered in cuproptosis, while cytoplasmic microviscosity acts as a straightforward biophysical marker to reflect cellular pathological shifts. In this research, we designed a novel near-infrared (NIR) dual-signal fluorescent sensor named Vis-HClO to realize simultaneous quantitative tracking of endogenous HClO and cytoplasmic viscosity within living tumor cells. The N,N-dimethyl aromatic segment serves as a rotating molecular unit to report viscosity variations via twisted intramolecular charge transfer (TICT), and the N,N-dimethylthiocarbamate fragment is constructed as a highly exclusive recognition unit for HClO capture. This sensor delivers two spectrally separated fluorescence signals: a NIR emission peak at 675 nm for viscosity quantification and an independent 600 nm emission band dedicated to HClO detection. Equipped with outstanding anti-interference capability, an ultralow limit of detection (LOD = 31.7 nM) and excellent cellular compatibility, Vis-HClO was successfully applied to two-channel confocal imaging of cuproptosis in A549 cells. This molecular optical sensor provides a robust analytical platform to decode microenvironmental transformations linked to copper-dependent cell death, and delivers innovative ideas for developing antitumor therapeutic schemes targeting cuproptosis regulation.