A fluorescent chemosensor for Hg(II) optical recognition: Mesoporous MCM-41 functionalized with a covalently linked Eu(III) complex

Mercury widely spreads in atmosphere, lithosphere, and surface water. Concentrated mercury levels could be harmful for individuals with neurological diseases because of bioaccumulation of mercury within brains and kidneys. Mercury is thus considered to be a very dangerous element by the United States Environmental Protection Agency due to the severe immunotoxic, genotoxic, and neurotoxic effects. Consequently, the detection of mercury ions is an important issue for environment and human health. An easily synthesized Eu(III) complex of Eu(PTA) is covalently grafted to the ordered functionalized mesoporous MCM-41 backbone, hoping to explore a novel fluorescence chemosensor with high sensitivity and selectivity for Hg(II) detection in aqueous solution. Fourier transform IR, Small-angle X-ray diffraction, High-Resolution TEM, Nitrogen adsorption/desorption, UV-vis absorption and emission have been employed to characterize the organically modified mesoporous material. The Eu-MCM-41 based chemosensor exhibits a high selectivity for Hg(II), and has a good linearity within the range of 1-12 mu mol/L in aqueous solution, suggesting the possibility for real-time qualitative or quantitative detection of Hg(II), as well as a wide potential application in environmental monitoring. The recognition of Hg(II) in actual samples from different sources has been examined by this chemosensor. Additionally, the sensing mechanism of Eu-MCM-41 based chemosensor towards Hg(II) is also investigated and discussed in detail. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Mercury is a hazardous element widely found in the atmosphere, lithosphere, and surface water. The detection of mercury ions is crucial for environmental and human health. A novel fluorescence chemosensor based on Eu-MCM-41 has been developed for high sensitivity and selectivity in Hg(II) detection in aqueous solution, with potential applications in environmental monitoring.