A nano-molar level fluorogenic and oxidation state-selective chromogenic dual reversible chemosensor for multiple targets, Cu2+/S2?and Fe3+/F?ions

Abstract

A pyridine-pyrazole-pyrene-based chemosensor,L, has been developed and fully characterized by all the possible techniques (ESI-MS, NMR, CHN, IRetc.). It has been found that the probe,L, selectively recognizes Cu2+ion and Fe3+ion fluorogenically and chromogenically, respectively, among a wide range of competitive metal ions. It has been demonstrated that the probe is not only metal ion-selective but also oxidation state-selective for Fe3+ions. The metal complexes (Cu and Fe) of the ligand were synthesized and characterized using different spectroscopic techniques and they were also characterised X-ray structurally as well, which confirm the stoichiometry (L?:?M = 2?:?1). The sensitivities for the fluorogenic sensing of Cu2+ions and chromogenic sensing of Fe3+have been found to be as low as nano molar level detection (69 nM and 27 nM, respectively). Further studies reveal that the CuIIL2complex can act as a �turn-off� fluorescent chemosensor for S2?ions and FeIIIL2can act as a reversible �turn-off� colorimetric chemosensor for F?ions over other anions. � The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2020.