Simultaneous detection and separation of uranium based on a fluorescent amidoxime-functionalized covalent organic polymer

To ensure the long-term sustainable development of nuclear energy as well as the prevention and control of uranium pollution, new materials that can simultaneously detect and separate uranium are still urgently needed. Herein, a new fluorescent covalent organic polymer (COP), namely HT-COP-AO, was synthesized and employed as both the fluorescent probe and absorbent for simultaneous uranium detection and separation considering its excellent fluorescence property and strong uranium coordination ability. The results showed that the fluores-cence of HT-COP-AO was quickly quenched by uranium within 2 min, and the limit of detection was 0.23 mu M (3 sigma/K). Further studies implied that uranium was coordinated with the amidoxime groups of HT-COP-AO through U-N and O = U = O bonds, which resulted in electron transfer from uranium to HT-COP-AO and quenching the fluorescence of HT-COP-AO consequently. Meanwhile, HT-COP-AO exhibited excellent absorption ability towards uranium, and the maximum absorption capacity (qmax = 401.3 mg/g) was higher than most reported amidoxime modified materials. The HT-COP-AO also showed high selectivity for both uranium detection and separation which makes it a great promising for uranium monitoring in real water samples.

Automated summary

In order to ensure the long-term sustainable development of nuclear energy and prevent uranium pollution, there is an urgent need for new materials that can detect and separate uranium simultaneously. In this study, a new fluorescent covalent organic polymer (COP) named HT-COP-AO was synthesized and used as a fluorescent probe and absorbent for uranium detection and separation. The results showed that HT-COP-AO had a strong fluorescence quenching effect on uranium with a detection limit of 0.23 μM. It was found that uranium was coordinated with the amidoxime groups of HT-COP-AO through U-N and O = U = O bonds, leading to electron transfer and fluorescence quenching.