Colorimtric and “turn-on” fluorescent for Hg2+ based on rhodamine-3,4-ethylenedioxythiophene derivative

We designed a novel fluorescent chemosensor for Hg2+ imaging in living cells based on rhodamine hydrazone and 3,4-ethylenedioxythiophene (EDOT). The selective fluorescence response of 1 to Hg2+ is due to the Hg2+-promoted desulfurization of the thiocarbonyl moiety, leading to the ring-opening of rhodamine B moiety of 1. The titration results show a 2:1 complex formation between 1 and Hg2+. The reversibility of chemosensor 1 is verified through its spectral response toward Hg2+ and S2− titration experiments. Chemosensor 1 can be utilized as an inhibit logic gate at molecular level.