Spectroscopic and theoretical studies on a novel bis(salamo)-like probe for highly effective fluorimetric-colorimetric identification of Fe and Cu in aquo-organic medium.

A novel bis(salamo)-type sensor FT for fluorescence-colorimetric recognition of Fe/Cu has been created, which revealed significant fluorescent performance and colorimetric sensing ability for Cu and Fe ions, superior to other related competitive metal ions. Interestingly, the binding of the FT probe with Cu ions manifested an instant color change from colorless to red in sunlight, which is detectable by the naked-eye, and a fluorescence turn-off response under UV light for Fe and Cu. The results demonstrated that the probe exhibits better sensitivity, greater affinity and lower limit of detection leading to quick response time in an aquo-organic medium. The excited state property of the FT probe and in the presence of Cu/Fe was evaluated on the basis of DFT & TD-DFT results. Furthermore, test strips have been provided for convenient monitoring of Cu and Fe ions by naked eye and fluorescence method.