Highly sensitive detection of mercury(II) and silver(I) ions in aqueous solution via a chromene-functionalized imidazophenazine derivative

In this work, we designed and synthesized a chromene-functionalized imidazophenazine-based fluorescent sensor (PS) which can detect mercury ions and silver ion in aqueous solution by different fluorescence behavior. When Hg2+ was added to the solution of PS, the fluorescent color of PS changed from yellow to green, and the emission peak was shifted from 543 nm to 511 nm. Upon the addition of Ag+, the fluorescence of PS was quenched. The detection limits of the PS for Hg2+ and Ag+ were calculated as 1.2 x 10(-7) M and 3.6 x 10(-8) M, respectively. In addition, the Ag+-coordinated non-fluorescent complex (PS-Ag+) could be used as new chemosensor for selective fluorescent turn-on detection of Hg2+ through competitive coordination in aqueous solution with a detection limit of 1.5 x 10(-8) M.