Development of a NIR Iridium(III) Complex-Based Probe for the Selective Detection of Iron(II) Ions

As a commonly used metal ion, iron(II) (Fe²⁺) ions pose a potential threat to ecosystems and human health. Therefore, it is particularly important to develop analytical techniques for the rapid and accurate detection of Fe²⁺ ions. However, the development of near-infrared (NIR) luminescence probes with good photostability for Fe²⁺ ions remain challenging. In this work, we report a novel iridium(III) complex-based luminescence probe for the sensitive and rapid detection of Fe²⁺ ions in a solution based on an Fe²⁺-mediated reduction reaction. This probe is capable of sensitively detecting Fe²⁺ ions with a limit of detection (LOD) of 0.26 μM. Furthermore, this probe shows high photostability, and its luminescence remains stable under 365 nm irradiation over a time period of 30 min. To our knowledge, this is first iridium(III) complex-based NIR probe for the detection of Fe²⁺ ions. We believe that this work provides a new method for the detection of Fe²⁺ ions and has great potential for future applications in water quality testing and human monitoring.