Highly selective and sensitive fluorescent probe for the rapid detection of mercury ions

Mercury (Hg) is one of the major toxic heavy metals, harmful to the environment and human health. Thus, it is significantly important to find an easy and quick method to detect Hg²⁺. In this study, we designed and synthesized a simple fluorescent probe with excellent properties, such as high sensitivity and selectivity, rapid response, and outstanding water solubility. When Hg²⁺ (5 μM) was added to the probe solution, it exhibited a very large fluorescent enhancement (about 350-fold stronger than the free probe) with the help of hydrogen peroxide (H₂O₂). Probe HCDC could quantitatively detect Hg²⁺ in the range of 0-10 μM using the fluorescence spectroscopy method and the detection limit was measured to be about 0.3 nM (based on a 3σ/slope). Analytical application was also studied, and the probe HCDC exhibited excellent response to Hg²⁺ with the addition of H₂O₂ in real water samples. So, our proposed probe HCDC provided a practical and promising method for determining Hg²⁺ in the environment.