Innovative Fluorescent Probe Enables Rapid Detection of Mercury in Water, Food Samples, and Live Cells

Mercury contamination poses a significant risk to human health because of its persistence in the environment and the potential for bioaccumulation through the food chain. To address this challenge, scientists from the People’s Hospital of Zhengzhou University and Luoyang Normal University have developed an innovative fluorescent probe for the selective and real-time detection of mercury ions (Hg²⁺). Their research, published in the Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, presents a breakthrough in mercury detection techniques (1).

Small mercury (Hg) metal sign with drops | Image Credit: © alexus - stock.adobe.com

The team designed and synthesized a novel fluorescent probe called (E)-O-(4-(2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl) O-phenyl carbonothioate (ICM-Hg). This probe demonstrated remarkable selectivity and sensitivity in detecting Hg²⁺ in various samples, including water, food, and live cells.

ICM-Hg operates through an intramolecular charge transfer (ICT) process, which is the basis of its mercury detection mechanism. When ICM-Hg comes into contact with mercury ions (Hg²⁺), it triggers an ICT process within the probe molecule. This process leads to a distinct color change from colorless to bright yellow and a significant increase in yellow fluorescence emission, allowing for the selective and sensitive detection of mercury ions. With ICM-Hg the presence of Hg²⁺ triggers this distinct color change from colorless to bright yellow. The fluorescence emission at 585 nm exhibited a linear relationship within the concentration range of Hg²⁺ (0–45 μM). The detection limit for Hg²⁺ was calculated to be 231 nM, highlighting the probe's high sensitivity.

One of the significant advantages of ICM-Hg is its ability to detect Hg²⁺ in real samples, such as tap water, tea, shrimp, and crab. The probe demonstrated excellent quantitative recovery, ensuring accurate analysis of Hg²⁺ contamination in these commonly encountered samples.

In addition to environmental and food sample analysis, the researchers successfully applied ICM-Hg for intracellular fluorescence imaging. This capability allows for the visualization and tracking of Hg²⁺ within live cells, opening new avenues for studying the distribution and behavior of mercury ions in biological systems.

The development of this innovative fluorescent probe provides a rapid and reliable method for detecting and monitoring mercury contamination in water, food, and living organisms. The high selectivity, sensitivity, and real-time detection capabilities of ICM-Hg hold immense promise for environmental monitoring, food safety, and biomedical applications.

Reference

(1) Li, X.; Chu, D.; Wang, J.; Qi, Y.; Yuan, W.; Li, J. Zhou, Z.A dicyanoisophorone-based ICT fluorescent probe for the detection of Hg²⁺ in water/food sample analysis and live cell imaging. Spectrochimica Acta Part A: Mol. Biomol. Spectrosc. 2023, 295, 122678. DOI:10.1016/j.saa.2023.122678