A ratiometric fluorescent probe for visualization of thiophenol and its applications

Thiophenol has a broad application in agriculture and industry. However, thiophenol can harm to the environment and health for its high toxicity. Developing an effective method for detection of thiophenol in the field of environmental and biology is valuable. In this work, we construct a reaction-based ratiometric fluorescent probe (E)-4-(2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)vinyl)-1-(4-(2,4-dinitrophenoxy)benzyl)pyridin-1-ium bromide (DCVP-DNP) for probing thiophenol in environment and cells by employing (E)-7-(diethylamino)-3-(2-(pyridin-4-yl)vinyl)-2H-chromen-2-one (DCVP) as the fluorophore and 2,4-dinitrophenyl (DNP) ether as the recognition group for the first time. The probe has high selectivity for thiophenol though thiophenol-triggered nucleophilic substitution reaction. In addition, the ratio of emission intensities of the probe has linearly with thiophenol concentration in the range of 0-65 μM and the detection limit of thiophenol is as low as 4.8 × 10^-8 M. Moreover, the probe can not only be applied for detection of thiophenol in water samples, but also image thiophenol in living cells, suggesting its potential application in environment and biological system.