Semiconducting polymer-based ratiometric fluorescent nanoprobe for highly accurate imaging of H₂S in inflammatory and...

Hydrogen sulfide (H₂S), as a vital gaseous signaling molecule, is widely involved in diverse physiological and pathological processes, and its aberrant levels are closely associated with numerous diseases. Conventional H₂S fluorescent probes mainly rely on single-channel on-off responses, which are susceptible to signal interference derived from uneven probe distribution and complex biological microenvironment.

we constructed a semiconducting polymer-based ratiometric nanoprobe (named SPNC) for H₂S imaging in inflammatory and tumor cells. SPNC displays a distinct ratiometric fluorescence response toward H₂S via H₂S-mediated FRET switching, characterized by well-resolved emission changes at 600 nm and 650 nm. The probe exhibits high sensitivity with a detection limit of 15.89 μM and excellent selectivity toward H₂S. Importantly, the ratiometric signal effectively eliminates concentration-dependent signal fluctuations, guaranteeing reliable detection in biological systems. Benefiting from favorable biocompatibility, SPNC was successfully applied for the ratiometric imaging of endogenous H₂S in RAW264.7 macrophages and HCT116 colorectal cancer cells, enabling high-contrast visualization and precise mapping of intracellular H₂S distribution.

This work provides a robust and reliable strategy for H₂S detection and may offer a promising tool for investigating the biological roles of H₂S in inflammation- and cancer-related processes.