The construction of an effective far-red fluorescent and colorimetric platform containing a merocyanine core for the specific and visual detection of thiophenol in both aqueous medium and living cells

Abstract

Thiophenol (PhSH) is toxic to the environment and biological systems although it is an indispensable material in the synthetic processes of chemical products. In this work, we designed and synthesized a malonitrile-based colorimetric and deep-red emission fluorescent dosimeter specifically for thiophenol detection by switching on the intramolecular charge transfer process. The 2,4-dinitrobenzene moiety in the probe could be cleaved by thiophenol, which led to strong deep-red fluorescence increase at 645 nm (50-fold) with a low detection limit of 9 nM. The maximum plateau of emission intensity was reached in about 30 min after the addition of thiophenol. Simultaneously, the presence of thiophenol could result in a prominent color change from orange to blue. Furthermore, the dosimeter could quantitatively sense thiophenol spiked in water samples and successfully visualize thiophenol in living SH-SY5Y cells.