Fast Response Fluorescent Probe with a Large Stokes Shift for Thiophenol Detection in Water Samples and Cell Imaging

Herein, the 2,4-dinitrophenyl functional group acting as the thiophenol reactive site was introduced into a carbazole–chalcone fluorophore to synthesize probe-CCF2, which could result in a remarkable increase in fluorescence when reacting with thiophenols. The selectivity and accuracy of probe-CCF2 were investigated with thiophenols, hydrosulphide salt, aliphatic thiols, glutathione, cysteine, anions and metal cations. Probe-CCF2 exhibited a detection limit of 37 nmol/L (R2 = 0.9951), a remarkable Stokes shift of approximately 130 nm, and a brief response time of 9 min with a remarkable increase in fluorescence of 90-fold. Probe-CCF2 was applied for thiophenol detection in water samples and imaging in living cells successfully, with high sensitivity and excellent selectivity.