A highly selective and ratiometric sensor for Hg2+ based on a phosphorescent iridium (III) complex

A new neutral iridium (III) complex Ir(TBT)2(acac) based on 2-thiophen-2-yl-benzothiazole (TBTH) ligands has been synthesized and characterized. Ir(TBT)2(acac) exhibited color change from red to orange without and with Hg2+, at the same time has a blue shift about 23 nm in fluorescent emission spectra. So it can serve as a highly selective chemodosimeter for Hg2+ with ratiometric and naked-eye detection. The sensor allowed determination of Hg2+ in the working range of 3 μM–10 μM with a detection limit of 2.14 μM. The phosphorescent chemosensor exhibited excellent selectivity and sensitivity for Hg2+ detection.