Portable ratiometric fluorescence sensor based on CuNCs@EuMOFs for visual detection of Hg(ii) in water samples.

Mercury ions (Hg) are highly toxic and bioaccumulative, posing a serious threat to the environment and human health. Traditional analytical techniques are limited by cost, portability and real-time monitoring capabilities, and there is an urgent need for sensitive and portable detection methods. In this study, copper nanoclusters (CuNCs) were encapsulated in red-emitting europium metal-organic frameworks (Eu-MOFs), and a ratiometric fluorescence probe based on CuNCs@EuMOFs was constructed and used for the detection of Hg in water extracts of traditional Chinese medicine samples and river samples. In the presence of Hg, the fluorescence of this probe is enhanced at 450 nm and weakened at 618 nm. Visual quantification can be performed using a smart phone based on the color change. The linear range is 0-360 μM ( = 0.9986), and the detection limit is 0.94 nM. The sample recovery rate was 94.43-106.43% (RSD < 4.37%). This study provides a new strategy for the portable visual detection of Hg in complex matrices.