A NIR Dual-Channel Fluorescent Probe for Fluctuations of Intracellular Polarity and H₂O₂ and Its Applications for the Visualization of Inflammation and Ferroptosis

Hydrogen peroxide and polarity are closely related to many physiological activities and pathological processes. However, near-infrared fluorescent probes that are sensitive to both H₂O₂ and polarity are still scarce. Herein, we developed the first dual-channel near-infrared fluorescent probe NBO, with an AIE effect, enabling simultaneous monitoring of H₂O₂ and polarity. The probe presented high sensitivity, high selectivity, and low detection limit for H₂O₂. It also had high sensitivity to polarity, independent of pH and viscosity, with large Stokes shifts, good photostability, and low cytotoxicity. Moreover, NBO was able to detect both endogenous and exogenous H₂O₂ as well as polarity fluctuations in vivo as a method to effectively differentiate between cancer cells and normal cells. Importantly, it also could monitor the therapeutic effects of drugs in inflammation and iron-dead cells and mice. Based on NIR emission, NBO could be used as an imaging tool and a way to evaluate the therapeutic effect of drugs for inflammation and ferroptosis.