Ferroptosis is a burgeoning iron-dependent cell death form, and has close relation with hypochlorous acid (HClO). Exploring the fluctuation of the HClO level in livingcellsduringferroptosis could contribute to the profound study of the biological functions of HClO duringferroptosis. Here, we present a turn-on probe () for the imaging of intracellular HClO duringferroptosis. The probe utilized