Colorimetric Chemosensor for Cu 2+ and Fe 3+ Based on a meso -Triphenylamine-BODIPY Derivative.

Optical chemosensors are a practical tool for the detection and quantification of important analytes in biological and environmental fields, such as Cu 2+ and Fe 3+ . To the best of our knowledge, a BODIPY derivative capable of detecting Cu 2+ and Fe 3+ simultaneously through a colorimetric response has not yet been described in the literature. In this work, a meso -triphenylamine-BODIPY derivative is reported for the highly selective detection of Cu 2+ and Fe 3+ . In the preliminary chemosensing study, this compound showed a significant color change from yellow to blue-green in the presence of Cu 2+ and Fe 3+ . With only one equivalent of cation, a change in the absorption band of the compound and the appearance of a new band around 700 nm were observed. Furthermore, only 10 equivalents of Cu 2+ /Fe 3+ were needed to reach the absorption plateau in the UV-visible titrations. Compound 1 showed excellent sensitivity toward Cu 2+ and Fe 3+ detection, with LODs of 0.63 µM and 1.06 µM, respectively. The binding constant calculation indicated a strong complexation between compound 1 and Cu 2+ /Fe 3+ ions. The 1 H and 19 F NMR titrations showed that an increasing concentration of cations induced a broadening and shifting of the aromatic region peaks, as well as the disappearance of the original fluorine peaks of the BODIPY core, which suggests that the ligand-metal (1:2) interaction may occur through the triphenylamino group and the BODIPY core.