A highly efficient and selective probe for F− detection based on 1H-imidazo[4,5-b]phenazine derivative

A new colorimetric and fluorimetric chemosensor for F− detection based on 1H-imidazo[4,5-b]phenazine derivative has been designed and synthesized. It shows excellent fluorescent specific selectivity and sensitivity for F− in DMSO solution. Upon addition of F− to the solution of probe 1, a remarkable color change from yellow to red could be observed easily by the naked-eye. The detection limit of this probe toward F− is 6.2 × 10−6 mol/L. Analysis by 1H NMR proved that the imidazolyl N–H could be hydrogen-bonded with added fluoride anions, and results in the difference of colors.