A highly selective coumarin-based chemosensor for dual sensing of Cu 2+ and Zn 2+ ions with logic gate integration and live cell imaging.

In this paper, a coumarin-based Schiff base chemosensor has been synthesized and developed to detect Cu 2+ and Zn 2+ ions in nanomolar concentrations. The probe selectively distinguishes Cu 2+ and Zn 2+ from among several metal ions in DMF : H 2 O (7 : 3, v/v, pH 7.4) HEPES buffer. The structure of the probe and its sensing behavior were investigated by FT-IR, UV-vis, fluorescence, HRMS, and NMR analyses, along with X-ray crystallography and computational studies. CIH detects Zn 2+ and Cu 2+ using different strategies: CHEF-induced fluorescence enhancement and paramagnetic fluorescence quenching, respectively. Job's plots show a 1 : 1 binding interaction between CIH and Cu 2+ or Zn 2+ ions. The binding constant values for Cu 2+ (1.237 × 10 5 M -1 ) and Zn 2+ (1.24 × 10 4 M -1 ) suggest a better ability for Cu 2+ to interact with CIH than Zn 2+ . An extremely high sensitivity of the probe was highlighted by its very low detection limits (LOD) of 5.36 nM for Cu 2+ and 3.49 nM for Zn 2+ . The regeneration of the probe with the addition of EDTA in its complexes allows the formation of molecular logic gates. CIH has been successfully employed in mitotracking and intracellular detection of Zn 2+ and Cu 2+ in SiHa cells.