Hydrogen peroxide-responsive fluorescent probes based on aromatic imidazole derivatives: design, optimization and biomedical applications.
Zhu Yanshuang Y
Hydrogen peroxide (H2O2) is a key bioactive molecule involved in various physiological processes, including cellular signal transduction, oxidative stress regulation, and immune metabolism. Disruption of H2O2 homeostasis is closely associated with the initiation and progression of multiple diseases, particularly tumors. In this study, we leveraged the ultrahigh brightness of aromatic imidazole carbaldehyde derivatives to design a series of novel H2O2-responsive fluorescent probes. By integrating two distinct H2O2-responsive moieties with these highly luminescent fluorophores, we successfully synthesized the probes designated as BTI, BTB, PTI, and PTB, which could be specifically activated by exogenous or endogenous H2O2 in cancer cells. Among these probes, PTI exhibited highest sensitivity and best selectivity toward H2O2 in vitro (LOD = 77 nM), enabling H2O2 mapping in HEp-2 cells and image-guided surgery in mouse models bearing subcutaneous tumors. Meanwhile, upon light irradiation, PTI exhibits efficient reactive oxygen species (ROS) generation and effective suppression of HEp-2 cell viability, positioning it as a promising photosensitizer for photodynamic therapy (PDT) in the treatment of laryngeal squamous cell carcinoma (LSCC).