Oxidation of tellurium dyes induced by mercury: More insights on the naked-eye and fluorescent Hg2+ detection

A new fluorescent probe based on Tellurium-Rhodamine (TR) was designed, synthetized and fully characterized by 1H NMR, 13C NMR, 125Te NMR, HRMS, IR and single crystal X-ray diffraction. A mechanism of Hg2+ detection, based on the oxidation of tellurium by Hg2+ was observed and fully understood. The new monomer chemosensor TR shows a high fluorescent quantum yield Φ = 0.41, excellent selectivity and good sensibility towards Hg2+, with a limit of detection of 2.95 μmol/L.