A novel dicyanisophorone-based colorimetric and ratiometric fluorescent probe for the detection of hypochlorite in the environment and living cells

A novel dual emissive fluorescent probe SFQ was designed and synthesized by linking dicyanisophorone and thiophene aldehyde units to carbazole groups. The probe SFQ has high selectivity and sensitivity toward ClO − . Upon addition of ClO − to the solution of probe SFQ resulted in a noticeable color changed from orange to pink under natural light. Meanwhile, SFQ could make a ratiometric fluorescence response to ClO − at two different excitation wavelengths, with the change of color from orange-red fluorescence to cyan fluorescence under the 365 nm UV lamp. The detection limit was 1.4 × 10 −7  mol/L under ratiometric conditions. The study on the reaction mechanism showed that when SFQ reacted with ClO − , the cyano group disappeared and the cyclic ketone SFQ -O came into being. Furthermore, probe SFQ was successfully used to monitor ClO − in HepG2 cells and detect ClO − in actual environmental water samples.