Chemical synthesis and analytical profiling of NTSH: a versatile probe for hydrogen sulfide sensing and cellular imaging

The development of novel probes featuring diverse structural motifs, with promising applications in H 2 S detection and cellular imaging remains a central focus of scientific research. This study details the synthesis of 4-methyl-N-(6-nitro-1,3-dioxo-1 H -benzo[ de ]isoquinolin-2(3 H )-yl)benzenesulfonamide (NTSH), which involves a condensation reaction between commercially available 4-nitro-1,8-naphthalic anhydride and p -toluenesulfonyl hydrazide in glacial acetic acid. The H 2 S probe exhibits detection limits of 166 μM in fluorometric, 15.08 mM in absorbance, 2.48 mM in colorimetric, and 29 nM in electrochemical studies. The versatility of NTSH in sensing endogenous H 2 S and bioimaging of HEK 293T cells highlights its potential applicability in chemical biology research. The tendency of NTSH to undergo chemical changes in the presence of H 2 S to induce noticeable optical and electrochemical responses could lay the groundwork for creating sensitive and selective sensing platforms.