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 (UO(2)(2-)). The fluorescence of UO(2)(2-) in its acid complex is further enhanced by more than two orders of magnitude following the addition of Y(3+); 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 clue to co-fluorescence. (C) 2011 Elsevier B.V. All rights reserved.