Enhancement of uranyl fluorescence using trimesic acid: Ligand sensitization and co-fluorescence

Trimesic acid (TMA) was shown to sensitize and enhance uranyl fluorescence in aqueous medium, with the enhancement being a maximum at pH 5.0. Fluorescence spectra and lifetime data together suggest that TMA complexes with uranyl (UO22+). The fluorescence of UO22+ in its acid complex is further enhanced by more than two orders of magnitude following the addition of Y3+; a process referred to as co-fluorescence, leading to the possibility of detecting uranium at sub ng/mL level. The present study demonstrates, for the first time, fluorescence enhancement of the uranyl species due to co-fluorescence. - Highlights: → Trimesic acid was shown to sensitize and enhance the fluorescence of uranium in aqueous medium. → This ligand also exhibited co-fluorescence of uranium with Y3+. → To the best of our knowledge this is the first report of co-fluorescence in uranium. → The enhancement of uranium fluorescence, resulted in detection limits in the ng/mL regime.