Ratiometric detection of Cu in water and drinks using Tb(III)-functionalized UiO-66-type metal-organic frameworks.

As an important trace element in the human body, the concentration of Cu has an important impact on the environment and human health, and its quantitative determination is of great significance in the fields of environmental protection and food safety. Here, a ratiometric fluorescent probe based on Tb(III)-functionalized UiO-66-type MOFs has been synthesized a facile post-synthetic modification method by employing mixed linkers containing terephthalic acid and 2,6-pyridinedicarboxylic acid for Cu detection. The blue fluorescence intensity at 440 nm from the ligands of MOFs does not change much with increasing Cu concentrations and can be used as a reference signal, while the green fluorescence of Tb can be rapidly and selectively quenched, causing fluorescence intensity at 547 nm to decrease. The probe can be used as a ratiometric sensor for Cu detection with a good linear response and low detection limit. The use of the probe for the determination of Cu in real water samples and drinks shows good practicality. This method for Cu detection is simple, specific and visualized to meet the needs of environmental monitoring and food analysis and provides a new strategy for the construction of new copper ion fluorescent sensors to analyze complex samples.