A terpyridine-based chemosensor for detection transition metal ions in aqueous solution: Synthesis and characterization

Abstract

A hydrophilic terpyridine-based copolymer chemosensor containing acrylic acid and fluorescence fragments to detect transition metal ions in aqueous solution were synthesized and well characterized. Characteristic color changes, which were resulted from chelating with specific metal ions and visible to the naked eye under natural and ultraviolet light provided possibility for real-time monitoring. Absorption and luminescence properties were adopted for further study, which exhibited unique response when treated with various metal ions. Intensity of absorption peak at 284 nm decreased with the increase of all kinds of metal ions while the secondary absorption peak at 335 nm increased with a certain concentration range. Different metal ions bring fluorescence enhancement or quenching response to the copolymer in aqueous solution. The unique fluorescence enhancing resulting from coordination of terpyridine and Zn2+ endows the polymer excellent detection ability. In particular, owing to metal-ligand charge transfer (MLCT) process, a new absorption peak appeared at 570 nm with the addition of Fe2+, and the polymer showed obvious color change.