A Sulfo-Cyanine Dye as a Colorimetric Chemosensor for Metal Cation Recognition

Metal cations play important roles in several industrial and biochemical processes. However, high levels of some cations are toxic and consequently cause serious health and environmental problems. Because of these features, the search for organic molecules capable of coordinating these analytes is an increasingly studied topic in the scientific community, especially those with optical responses (optical chemosensors). Following the research group’s interest in heterocyclic optical chemosensors for various ions, a sulfo-cyanine, which absorbs and emits in the NIR region, was studied as a chemosensor for the recognition of metal cations with biological and environmental relevance. Chemosensing studies showed that this sulfo-cyanine displayed a highly sensitive colorimetric response, from blue to colorless, for Cu2+ and Fe3+ in acetonitrile solution.