Construction of an effective far-red fluorescent and colorimetric platform containing a merocyanine core for specific and visual detection of thiophenol in both aqueous medium and living cells
Thiophenol (PhSH) is toxic to environment and biological system although it is an indispensable material in synthetic processes of chemical products. In this work, we design and synthesize 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 can be cleaved off by thiophenol, which leads to a strong deep-red fluorescence increase at 645 nm (50-fold) with a low detect limit of 9 nM. The maximum plateau of emission intensity was reached in about 30 min since addition of thiophenol. Simultaneously, the presence of thiophenol can result in a prominent colorimetric change from orange to blue. Furthermore, the dosimeter can quantitatively sense thiophenol sparked in water samples and successfully visualize thiophenol in living SH-SY5Y cells.