Luminescence sensing of weakly-hydrated anions in aqueous solution by self-assembled europium(iii) complexes.

Self-assembled europium(iii) complexes produced dispersed nanoparticles with diameters of about 4-8 nm, which exhibited long-lived luminescence in a 20 wt% EtOH-H2O solution. The complexes could sense weakly hydrated anions, such as perchlorate, by a change in luminescence intensity using an anion displacement method.