Trace analysis of uranyl ion (UO2(2+)) in aqueous solution by fluorescence turn-on detection via aggregation induced emission enhancement effect.

A sensitive fluorescence turn-on method for trace amounts of uranyl ion (UO2(2+)) in solution has been developed in this study, based on aggregation induced emission enhancement (AIEE) characteristics of 4-pethoxycarboxyl salicylaldehyde azine (PCSA) induced by complex interaction between UO2(2+) and PCSA. Under optimized conditions, a fluorescence enhancement at 540 nm could be observed, which was linearly related to the concentration of UO2(2+) in the range of 1-25 ppb (part per billion). Analytical data showed that a detection limit of 0.2 ppb was achieved with the relative standard deviation (R.S.D.) 1.3% (n=5). The proposed method was successfully utilized in quantifying UO2(2+) in fuel processing wastewaters.