A highly selective on–off–on responsive lanthanide(iii) based probe for recognition of copper and hydrogen sulfide

Abstract

The development of a europium(III) based probe (EuL1) for the detection of Cu(II) ions and hydrogen sulphide is presented. With the addition of Cu(II) ions, EuL1 displayed the greatest quenching among the other cations examined. The binding constant was 74 026 ± 2899 M⁻¹. Once combined with Cu(II) ions, EuL1Cu demonstrated high specificity for hydrogen sulfide compared to other organic and inorganic sulfur compounds. EuL1Cu exhibited an on–off–on type luminescence change with the alternate addition of Cu(II) ions and H₂S along with reversible forming-separating of the complex.