A dual-emissive MOF for the simultaneous detection of tetrachlorobenzoquinone isomers in their mixtures

Metal-organic frameworks (MOFs) have become an important class of fluorescence sensing materials. In spite of the application value of multi-responsive MOF sensors and the great efforts made on them, the simultaneous detection of multiple analytes in mixtures is still a big challenge due to the cross interference among different analytes. The incorporation of multiple responsive components to increase the signal channels is a promising way to solve this problem. In this work, a stable and dual emissive MOF was constructed by the incorporation of Tb3+ and 2-aminoterephthalate into the backbone of UiO-66. This MOF was used for the analysis of the two isomers of tetrachlorobenzoquinone (o- and p-TCBQs). It was observed that o-TCBQ could give a ratiometric fluorescence signal, while p-TCBQ quenches all the emission peaks equally. Because the signals of these two compounds are in different forms and could be split, this MOF was successfully applied to the simultaneous quantification of o- and p-TCBQs in their mixtures.