Dual quenching strategy for sensitive detection of toxic thiolphenols based on a NIR-illuminant platform with a large Stokes shift

Abstract In view of thiophenol contaminants and their adverse effects in environment, it is valuable to develop an effective probe for thiophenols. Based on a large Stokes shift (126 nm) NIR-illuminant platform (Compound 2 ), we developed a colorimetric and “off-on” near-infrared (NIR) fluorescent probe ( NIRP ) to selectively discriminate thiophenols from various analytes including aliphatic thiols. NIRP is dually quenched (ICT blocked quenching and PET quenching), thus achieving large signal-to-noise ratio and high sensitivity for thiophenol detection. For the first time, the unique NIR-illuminant phenomenon of 2′ and the d-PET quenching process on NIRP are revealed by the density functional theory (DFT) calculations. Moreover, we demonstrate the practical applications of NIRP , including the quantitative thiophenol detection in environmental water samples and NIR fluorescent imaging of thiophenol in HeLa cells.