Visualizing hydroxyl radical by a dual-channel NIR fluorescence chemosensor within biosystem.

Hydroxyl radicals (•OH) are the predominant oxidative species in living systems and are associated with various diseases and physiological disorders. Because of its extremely short lifetime and inherently low steady-state concentration, real-time detection of •OH in environmental and biological systems remains highly challenging, despite its critical regulatory function. In the present study, we report the design and successful synthesis of a novel dual-channel fluorescent probe, HR-YT, for sensitive •OH monitoring. The probe exhibits a fast response along with excellent sensitivity, achieving a detection limit as low as 28 nM. Importantly, owing to its low cytotoxicity, HR-YT is also suitable for detecting exogenous •OH in living cells, plant tissues, and zebrafish models. Furthermore, probe HR-YT has been used to screen the non-tumor macrophage cells from selected tumor cells when stimulated with β-Lapachone, demonstrating its potential applications in biological imaging.