A dual-responsive RhB-doped MOF probe for simultaneous recognition of Cu2+ and Fe3+

Abstract Based on the dual response of RhB@UiO-67 (1:6) to Cu 2+ and Fe 3+ , a proportional fluorescent probe with ( I 392 /I 581 ) as the output signal was developed to recognize Cu 2+ and Fe 3+ . 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 2+ and Fe 3+ at low concentrations. The proportional fluorescent probe RhB@UiO-67 (1:6) exhibited simultaneous quenching of Cu 2+ and Fe 3+ , which was found to be of interest. Furthermore, the limits of detection (LODs) for Cu 2+ and Fe 3+ 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 2+ and Fe 3+ in an ethanol medium. Additionally, RhB@UiO-67 (1:6) demonstrated exceptional immunity and reproducibility towards Cu 2+ and Fe 3+ . The observed fluorescence quenching of Cu 2+ and Fe 3+ 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 2+ and Fe 3+ sensing technologies.