Sensitive fluorescent chemosensor for Hg(II) in aqueous solution using 4'-dimethylaminochalcone

Mercury (Hg) is an element with high toxicity, especially to the nervous system, and fluorescent pigments are used to visualize dynamic processes in living cells. A little explored fluorescent core is chalcone. Herein, we synthesized chalcone (2E)-3-(4-(dimethylamino)phenyl)-1-phenylprop-2-en-1-one (8) and assessed its photophysical properties. Moreover, the application of this chemosensor in aqueous media shows a selective fluorescence quenching effect with Hg(II). The figures of merit for the chemosensor were calculated to be LOD = 136 nM and LOQ = 454 nM, as well as a stoichiometry of 1:1. Furthermore, the association constant (K_a) and fluorescence quenching constant (K_SV) were calculated using the Benesi-Hildebrand and Stern-Volmer equations to be K_a= 9.08 × 10⁴ and K_SV= 1.60 × 10⁵, respectively. Finally, by using a computational approach, we explain the interaction between chalcone (8) and Hg(II) and propose a potential quenching mechanism based on the blocking of photoinduced electron transfer.