Bimetallic Cd/Zr-UiO-66 material as a turn-on/off probe for As5+/Fe3+ in organic media.

In this work, a series of bimetallic Cd/Zr-UiO-66 materials were successfully synthesized for fluorescence sensing toward traces of As5+ and Fe3+ via a one-pot method. Interestingly, the obtained bimetallic Cd/Zr-UiO-66 (1:9) can be served as turn-on probe for As5+ as well as turn-off probe for Fe3+. The LODs of Cd/Zr-UiO-66 (1:9) toward As5+ and Fe3+ were calculated to be 5.4 μM and 4.3 μM, respectively, indicating its effective sensing properties for As5+ and Fe3+ in methanol media. Moreover, even in the presence of other potentially interfering toxic metal ions such as As3+, Cd2+ and Pb2+, Cd/Zr-UiO-66 (1:9) still presented good anti-interference abilities. Additionally, the removal efficiency of Cd/Zr-UiO-66 (1:9) toward As5+ was higher than 70% when the initial As5+ was lower than 50 mg/L. The fluorescence quenching of Fe3+ were mainly due to the competitive absorption of excitation source and RET, while the ACE mechanism was mostly responsible for the enhancement of As5+. More importantly, this job might pave the way for future researches and applications on sensing As5+ and Fe3+.