Design and fabrication of a new fluorescent film sensor towards uranyl ion via self-assembled monolayer

Uranium, as a naturally radioactive actinide element, plays a significant role in the nuclear industry. It is reasonably necessary to develop a fast and efficient approach for uranyl ions detection. In consideration of the practical application, fluorescent film sensor exhibits great advantages of convenience, ease of being made into portable devices, etc. Herein, a new film senor towards uranyl ion has been designed and fabricated via drawing into an AIE-active (aggregation-induced emission) tetraphenylethene moiety and a carbamoylphosphine oxide chelate moiety through a self-assembled monolayer on quartz glass. Fluorescence spectra measurements demonstrated that the film sensor could be used for detecting UO22+ in a simple way with the range of 0-0.5 mu M, and the calculated limit of detection was as low as 32 nM. On the basis of the results from XPS, NMR, MS, time-resolved fluorescence spectra and absorption spectra measurements, the fluorescence quenching was arising from the UO22+ located around the tetraphenylethene molecules under the ground state. Furthermore, the film sensor exhibit higher selectivity toward UO22+ than the other metal ions. These results suggest that the film sensor can be applied as a convenient sensor for the UO22+ detection.