Novel luminescent Schiff's base derivative with an azo moiety for ultraselective and sensitive chemosensor of Fe ions.

Chemosensors with ultrasensing capabilities for detection of metal ions have received particular attention when using luminescent organic compounds. Even though hundreds of chemosensor agents have been reported for Fe ion sensing, the designs of those molecules have been complicated and time consuming, in addition to having limited application for aquatic samples due to their poor hydrophilicity. Here, we synthesized a novel azo-imine derivative (L2) that showed ultrasensitive and selective sensing for Fe ions. L2 exhibited ultraselective detection of Fe ions with a turn-off of its emission intensity at 341 nm in H O:MeOH (4:1 v/v) aqueous medium. This quenching phenomenon was in good agreement with its colour change from orange-yellowish to colourless. Its capability was shown due to its very low limit of detection and limit of quantification values of 0.31 and 1.04 μM, respectively. The interference study showed that L2 is ultraselective for the detection of Fe ions without a significant reduction in its sensing capability even in competitive metal mixtures. Furthermore, direct Fe quantification of tap and drinking water showed that L2 gave good recovery percentages. These findings demonstrated that the Schiff's base with an azo fluorophore derivative is a potential chemosensor agent for Fe ions sensing applications in aqueous media.