Detection of H₂O₂ by a novel fluorescent probe based on the synergy of "ESIPT + ICT"

Hydrogen peroxide plays a crucial role in maintaining physiological homeostasis in the human body, so it is imperative to design a highly selective and sensitive fluorescent probe to monitor the content of H₂O₂ in organisms. Herein, we designed a probe with benzothiazole (HBT) as the main fluorophore backbone, which realized the molecular "ESIPT + ICT" synergistic luminescence effect. An effective response to detect H₂O₂ within 30 min was achieved by the probe HBT-B, with a detection limit of 1.73 μM and new peaks are presented after the detection of H₂O₂ in the UV-Vis absorption spectra, with a large Stoke's shift (105 nm). Furthermore, it is demonstrated that the probe HBT-B can be utilized in biological in vivo cellular imaging and has excellent biocompatibility to effectively detect H₂O₂ at the cellular level.