Enhancing the sensing selectivity of phosphatase-mimicking UiO-66 nanozyme through ligand perfluorination for selective detection and removal of Al3+

Nanozymes have attracted increasing attention in sensors owing to their capacity for catalytically converting substrates into colored or luminescent products. However, the lack of sensing selectivity limits their practical use. Herein, a ligand engineering strategy was proposed to improve the selectivity of UiO-66 nanozyme. Upon the perfluorination of bridging ligands, the resulting UiO-66-F 4 nanozyme exhibited higher phosphatase-like catalytic activity than the pristine UiO-66. More importantly, UiO-66-F 4 exhibited a remarkable specificity towards Al 3+ , which was ascribed to the specific coordination interaction of Al 3+ with F groups and oxygen-containing groups of UiO-66-F 4 . After incubation with Al 3+ , the aggregation of UiO-66-F 4 nanosheets occurred, which further results in the significant decrease in its catalytic activity. Base on this finding, a colorimetric method for selective detection of Al 3+ was proposed. The linear range is 2–30 μM with a detection limit as low as 0.27 μM. In addition, as an adsorbent for Al 3+ , UiO-66-F 4 also exhibited excellent adsorption performance with a capacity of 27.04 mg/g.