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

Background

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.

Results

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.

Significance

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.