A novel coumarin based molecular switch for dual sensing of Zn(ii) and Cu(ii)

Abstract

An efficient coumarin based molecular switch for the dual sensing of two environmentally as well as biologically important cations Zn²⁺ and Cu²⁺ has been synthesized. The receptor H₂L shows about 6 fold enhancement in fluorescence intensity upon the addition of Zn²⁺ and also exhibits quenching of emission intensity upon the addition of Cu²⁺ without interference of other metal ions present in solution. In the case of other metal ions no significant change in the emission intensity is observed. H₂L presents a tunable system comprising of two INHIBIT logic gates with Zn²⁺ and Cu²⁺ or Zn²⁺ and EDTA as chemical inputs by monitoring the emission mode. An IMPLICATION logic gate is obtained with Cu²⁺ and EDTA as chemical inputs and emission as the output mode.