A novel “turn-on” fluorescence probe based on azoaniline-arylimidazole dyad for the detection of Cu2+

•A novel fluorescence probe TPI-AD bearing azoaniline and arylimidazole moieties was synthesized and applied for Cu2+ detection.•The probe exhibited 220 fold fluorescence enhancement and a “naked-eye” visible color change.•The detection limit was down to 14.4 nM.•The application of probe in living cells was successfully realized.

A novel fluorescence probe TPI-AD bearing azoaniline and arylimidazole moieties is conveniently synthesized for the detection of Cu2+. A “naked-eye” visible color change from colorless to lake-blue together with a 220-fold fluorescence enhancement can be achieved by Cu2+-catalyzed oxidative cyclization, which transforms the non-emissive TPI-AD into strongly fluorescence benzotriazole derivative (TPI-BTA). The TPI-AD probe can be applied for quantitative detection of Cu2+ with good linear relationship between its fluorescence intensity and Cu2+ concentration. Moreover, TPI-AD shows high selectivity over other common metal ions as well as excellent sensitivity with a detection limit of 14.4 nM. In addition, the fluorescence imaging of living cells MCF-7 reveals the potential application of TPI-AD in biological system.

Graphical abstractA novel “turn-on” fluorescence probe TPI-AD based on azoaniline-arylimidazole dyad was synthesized for colorimetric and fluorometric detection of Cu2+ through Cu2+-catalyzed oxidation cyclization reaction.Download high-res image (313KB)Download full-size image