Phosphorescent chemosensors for metal cations based on heavy-metal complexes

Metal cations play very important roles in life and environmental sciences. The qualitative detection and quantitative determination of these metal cations are of great importance in biology and environmental monitoring. Phosphorescent heavy-metal complexes applied in chemosensors for metal cations have attracted increasing interest because they have some advantageous photophysical properties, such as evident Stokes shifts for easy separation of excitation and emission, significant single-photon excitation in the visible range and relatively long lifetimes, which makes their luminescence be easily identified from fluorescent backgrounds. The research progress in phosphorescent chemosensors for metal cations based on heavy-metal complexes is summarized, with focusing on the design principles and recent development of phosphorescent chemosensors for metal cations based on some heavy-metal complexes, such as Pt(II) -, Ru(II) -, Re(I) -, Ir(III) - and Au(I) -based complexes.