A highly efficient yet stable salamo-type fluorescent chemosensor with multiple responses to Cu2+ and S2−

Abstract

A new salamo-type bisoxime compound H₃L has been synthesized and exploited as a highly efficient chemosensor with multiple responses to Cu²⁺ and S²⁻. Chemosensor H₃L exhibits highly selective and sensitive detection of Cu²⁺ and S²⁻ simultaneously. The LODs of Cu²⁺ and S²⁻ were calculated to be 1.5398 × 10⁻⁷ and 1.7274 × 10⁻⁷ M in DMF-water (9 : 1, v/v) solution, respectively. The color of the chemosensor H₃L solution changed from light green to dark green after adding S²⁻ under a 365 nm UV-lamp. The sensing mechanism of the chemosensor H₃L was characterized using several methods, including ultraviolet spectroscopy, ESI-mass spectrometry, ¹H-NMR and FT-IR spectroscopy. Meanwhile, the crystal structure of the Cu(II) complex, [Cu₂(L)]ClO₄·2CH₃OH, has been determined by X-ray crystallographic analysis. Density Functional Theory (DFT) was employed to further understand the obtained experimental results.