Construction of a lysosome-targetable ratiometric fluorescent probe for H2O2 tracing and imaging in living cells and an inflamed model

Abstract

Hydrogen peroxide (H₂O₂), an important reactive oxygen species (ROS) with unique destructive oxidation properties, can be produced in lysosomes to fight off pathogens. Although many fluorescent probes have been developed for the detection and imaging of H₂O₂, the development of a ratiometric fluorescent probe for H₂O₂ detection and imaging in lysosomes and an inflammation model remains rather scarce. Therefore, it is important to develop an efficient tool for monitoring H₂O₂ in inflamed tissues to evaluate the physiological and pathological relationship between inflammation and lysosomal H₂O₂. In this work, a new naphthalimide-based lysosome-targeting fluorescent probe (NPT-H₂O₂) for ratiometric detection and imaging was developed in vitro and in vivo. The probe exhibited two well-resolved emission peaks separated by 125 nm, rapid response (<40 s), and high selectivity and sensitivity toward H₂O₂, as well as low cytotoxicity in vitro. Inspired by prominent features of these results, we further successfully applied NPT-H₂O₂ for H₂O₂ imaging with a dual-channel in living cells, demonstrating that our probe NPT-H₂O₂ was targeted in the lysosomes. Finally, NPT-H₂O₂ was used for H₂O₂ detection in inflamed tissues and achieved satisfactory results. We predict that our probe can be used as a powerful tool to reveal the relationship between physiology and pathology of inflammation and lysosomal H₂O₂.