Functional groups assisted-photoinduced electron transfer-mediated highly fluorescent metal-organic framework quantum dot composite for selective detection of mercury (II) in water

The presence of toxic mercury (II) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms. Therefore, detection of mercury (II) in water is very much crucial and several researches are going on in this topic. Metal-organic frameworks (MOFs) are considered as an effective device for sensing of toxic heavy metal ions in water. The tunable functionalities with large surface area of highly semiconducting MOFs enhance its activity towards fluorescence sensing. In this study, we are reporting one highly selective and sensitive luminescent sensor for the detection of mercury (II) in water. A series of binary MOF composites were synthesized using in-situ solvothermal synthetic technique for fluorescence sensing of Hg2+ in water. The welldistributed graphitic carbon nitride quantum dots on porous zirconium-based MOF improve Hg2+ sensing activity in water owing to their great electronic and optical properties. The binary MOF composite (2) i.e., the sensor exhibited excellent limit of detection (LOD) value of 2.4 nmol/L for Hg2+. The sensor also exhibited excellent performance for mercury (II) detection in real water samples. The characterizations of the synthesized materials were done using various spectroscopic techniques and the fluorescence sensing mechanism was studied. (C) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Automated summary

A highly selective and sensitive luminescent sensor for the detection of mercury (II) in water has been reported in this study. The activity for Hg2+ sensing was improved by synthesizing binary MOF composites. The sensor also showed excellent performance in real water samples.