A dual-responsive RhB-doped MOF probe for simultaneous recognition of Cu and Fe.

Based on the dual response of RhB@UiO-67 (1:6) to Cu and Fe, a proportional fluorescent probe with (I/I) as the output signal was developed to recognize Cu and Fe. Developing highly sensitive and selective trace metal ions probes is crucial to human health and ecological sustainability. In this work, a series of ratio fluorescent probes (RhB@UiO-67) were successfully synthesized using a one-pot method to enable fluorescence sensing of Cu and Fe at low concentrations. The proportional fluorescent probe RhB@UiO-67 (1:6) exhibited simultaneous quenching of Cu and Fe, which was found to be of interest. Furthermore, the limits of detection (LODs) for Cu and Fe were determined to be 2.76 μM and 0.76 μM, respectively, for RhB@UiO-67 (1:6). These values were significantly superior to those reported for previous sensors, indicating the probe's effectiveness in detecting Cu and Fe in an ethanol medium. Additionally, RhB@UiO-67 (1:6) demonstrated exceptional immunity and reproducibility towards Cu and Fe. The observed fluorescence quenching of Cu and Fe was primarily attributed to the mechanisms of fluorescence resonance energy transfer (FRET), photoinduced electron transfer (PET), and competitive absorption (CA). This work establishes a valuable foundation for the future study and utilization of Cu and Fe sensing technologies.