A Turn-On Fluorescent Probe for Highly Selective Detection and Visualization of Hydrogen Sulfide in Fungi

Hydrogen sulfide (H₂S) is a significant actor in the virulence and pathogenicity of fungi. The analysis of endogenous H₂S in fungi benefits the prevention and treatment of pathogenic infections. Herein, a H₂S-activated turn-on fluorescent probe named DDX-DNP was developed for the sensitive and selective detection of H₂S. Using DDX-DNP, the ability of several oral fungi strains to produce H₂S was identified, which was also validated using a typical chromogenic medium. In addition, DDX-DNP was successfully used for the visual sensing of endogenous H₂S in fungal cells via microscope, flow cytometry, and colony imaging, along with a specific validation with the co-incubation of H₂S production inhibitors in living cells. Above all, DDX-DNP could be used for H₂S detection, the fluorescent imaging of fungi, and even the identification of related fungi.