A near-infrared fluorescent probe for tracking endogenous and exogenous H₂O₂ in cells and zebrafish

H₂O₂ is an important signaling molecule in the body, and its levels fluctuate in many pathological sites, therefore, it can be used as a biomarker for early diagnosis of disease. Since the environment in vivo is extremely complex, it is of great significance to develop a probe that can accurately monitor the fluctuation of H₂O₂ level without interference from other physiological processes. Based on this, we designed and synthesized two new near-infrared H₂O₂ fluorescent probes, LTA and LTQ, based on the ICT mechanism. Both of them have good responses to H₂O₂, but LTA has a faster response speed. In addition, the probe LTA has good biocompatibility, good water solubility, and a large Stokes shift (95 nm). The detection limit is 4.525 μM. The probe was successfully used to visually detect H₂O₂ in living cells and zebrafish and was successfully used to monitor the changes in H₂O₂ levels in zebrafish due to APAP-induced liver injury.