A fluorescent probe for rapid detection of low concentration mercury ions and its application in biological cells

As a toxic substance, mercury can easily cause harm to organisms and humans. The development of methods that allow rapid detection of low concentrations of mercury ions has a positive effect on the natural environment and human health. The fluorescent probe RBSH reported in this paper has a detection limit as low as 5.9 nM, and a fast response time and allows naked eye detection. We characterized its structure by nuclear magnetic resonance and mass spectrometry, and explored the response mechanism of the probe using Job's plot, and ¹H NMR and mass spectrometry. UV-vis spectrophotometry and fluorescence spectroscopy show the excellent optical properties of the probe RBSH. The low toxicity and high cell penetration capacity demonstrated by the cellular assay open up the possibility of biological experiments. By selecting hosts (natural water samples, soybean plants and zebrafish) where mercury ions are likely to be present in the biological chain for low concentration Hg²⁺ detection, the results all demonstrated the excellent performance of the probe RBSH.