A high-sensitivity ESIPT-based fluorescent probe with a large stokes shift for H₂S detection and imaging in U251 cells and glioma mouse models.

Abstract

Glioblastoma is a highly aggressive brain malignancy characterized by poor prognosis and limited survival, largely due to the absence of reliable tools for early diagnosis. Hydrogen sulfide (H₂S), a well-established gasotransmitter and disease-related biomarker, plays a crucial regulatory role in glioma progression. However, the dynamic variations of H₂S levels during glioblastoma development remain poorly characterized, hindering a deeper understanding of disease mechanisms and the advancement of therapeutic strategies. Here, we report the design and application of an ESIPT-based fluorescent probe, BBHS, specifically developed for H₂S detection. BBHS exhibits a pronounced fluorescence response, a large Stokes shift of 174 nm, remarkable sensitivity (limit of detection = 65 nM), and excellent selectivity over competing species under physiological conditions. Experimental data further confirm the capability of BBHS to monitor intracellular H₂S levels in living U251 glioma cells, as demonstrated by fluorescence imaging assays. Moreover, BBHS enables differentiation between malignant and normal cells through H₂S-specific imaging signals. Notably, BBHS also facilitates real-time in vivo imaging of H₂S in mice bearing U251 gliomas, providing valuable insights for early glioma detection and underscoring its potential utility in preclinical oncology research.