In-situ synthesis of carbon dots-embedded europium metal-organic frameworks for ratiometric fluorescence detection of Hg2+ in aqueous environment

A novel dual-emission ratiometric fluorescent sensor (CDs@Eu-MOFs) has been synthesized successfully by encapsulating water-soluble fluorescent CDs into the chambers of Eu-MOFs via a simple one-pot hydrothermal method, which can be used for the detection of Hg2+ in environmental water samples. The synthesized CDs@Eu-MOFs inherited simultaneously the excellent luminescence performance of Eu3+ and CDs and exhibited good structural and fluorescence stability in aqueous solution. The presence of Hg2+ changed the fluorescence intensity of CDs, while the fluorescence intensity of Eu-MOFs hardly changed, which could be used as the recognition part and the reference part respectively to construct the ratiometric fluorescence sensor. The obtained Hg2+ fluorescent probe showed a wide linear range (0 -300 mu M) and a low detection limit (0.12 nM). The developed method can be used as a multi-functional fluorescent sensor with high sensitivity and good selectivity for the determination of Hg2+ in actual water samples. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A novel dual-emission ratiometric fluorescent sensor (CDs@Eu-MOFs) was successfully synthesized for the detection of Hg2+ in environmental water samples, with wide linear range and low detection limit. The sensor showed excellent luminescence performance and good stability in aqueous solution.