A naphthalene–dansylhydrazine based ratiometric fluorescence probe for selectively detecting Cu2+

Abstract A ratiometric fluorescence probe for detecting Cu2+ was developed. The probe responded selectively to Cu2+ over other metal ions with a remarkable fluorescence change when being irradiated with 320 nm light. The emission peak showed a 196 nm blue shift from 575 nm to 379 nm, and the emission intensity was basically the same at two different emission wavelengths. According to the curve fitting of fluorescence titration data, it was suggested that probe 1 could be used to quantitatively detect the concentration of Cu2+. The detection limit of probe 1 for Cu2+ was estimated to be 0.18 μM, which was lower than the standard set by the U.S. Environmental Protection Agency (EPA). Additionally, the detection results of real water samples showed that the probe had a good recovery.