Investigation of UO2+2 Binding Sites on Datura Innoxia Using UO2+2 Luminescence

Abstract

A pulsed tunable dye laser has been used to obtain the emission spectra and fluorescence decay curves of solid UO²⁺₂- Datura innoxia and a series of UO²⁺₂-containing complexes at liquid nitrogen temperature. The decay curves of UO²⁺₂- Datura exhibited a bi-exponential decay, suggesting that at least two different binding sites are present on the walls of nonliving D. innoxia cells. The model solutions containing carboxyl, amine, hydroxyl, phosphoryl, sulfate, and sulfonate functionalities have been utilized to identify the functionalities involving in the binding of UO²⁺₂ to nonliving D. innoxia cell walls. Phosphoryl and dicarboxyl groups have been demonstrated to be the dominant functional groups responsible for the binding of uranyl ions on D. innoxia cell walls.