A new double-emission fluorescent probe for fast detection of thiophenols in aqueous solution and living cells.

A new fluorescent probe was designed and synthesized according to the photo-induced electron transfer theory (PET) and the results of density functional theory calculation. The synthesized probe had a larger Stokes shift (130 nm) and double emission peak in response to highly toxic thiophenols, which could be applied in rapid and high sensitive detection of thiophenol in aqueous solution. A 25-fold fluorescence intensity enhancement was achieved and the fluorescent intensity at 460 nm had a linear relationship to the thiophenol in concentration range of 0-2.0 μM. Furthermore, a remarkable detection limit (6 nM) could be achieved. 50-fold other species have no interference to the detection. The practical utility of the probe was demonstrated by live HeLa cells imaging and thiophenol detection in real water samples. In linear range of 0-2.0 μM, the probe showed good recoveries (from 95% to 108%) for thiophenol detection in natural water samples. This method possesses high sensitivity, lower detection limit and fast response (i.e., 10 min, which is shorter than the average time response of other reported methods), indicating that the synthesized probe would be promising for real-time detection of thiophenols.