A highly selective colorimetric chemodosimeter for fast and quantitative detection of hydrogen sulfide

Based on the fact that hydrogen sulfide (H₂S) possesses the smallest steric hindrance among thiols and the SH^- group adds faster to an electron-poor CC double bond, we designed and synthesized a tricyanoethylene-derived colorimetric chemodosimeter 1 for the fast and highly selective assay of H₂S. Chemodosimeter 1 exhibited excellent water-solubility due to the introduction of two hydrophilic hydroxyl groups. Upon the addition of Na₂S, chemodosimeter 1 showed a fast (complete within 400 s) and robust decrease of the absorption intensity (>97%), accompanied by a color change from red to colorless. Additionally, a linear relationship between absorption intensity and the added Na₂S concentrations (0-130 μM) was observed in aqueous buffer solution (pH 7.4, 20 mM PBS). Importantly, the proposed paradigm in this paper, adoption of the tricyanoethylene derivative as a recognition receptor to distinguish H ₂S from other thiols and analytes, provides a promising methodology for the design of colorimetric and fluorescent chemodosimeters for fast determination of H₂S.