Dye-embedded NanoMOF as a turn-on fluorescent sensor for selective and sensitive detection of hydrogen sulfide

Developing high-performance fluorescent probes for hydrogen sulfide (H 2 S) has drawn enormous attention recently. In this paper, we report a stable nanoscale dual-emitting probe RB@UiO-66-NO 2 for H 2 S detection, which was obtained by embedding the red-emitting rhodamine B (RB) in the blue-emitting nitryl-functionalized metal−organic framework (MOF) UiO-66-NO 2 . The accommodated RB is designed as a reference signal, and the nitro groups on the host skeleton can serve as accessible reactive sites to allow for the selective sensing of H 2 S by RB@UiO-66-NO 2 . As a result of H 2 S's ability to dioxide the nitro group on the ligand and improve the intramolecular charge transfer, RB@UiO-66-NO 2 shows enhanced blue fluorescence as well as ratiometric response to H 2 S. Our investigation shows that RB@UiO-66-NO 2 nanoprobe has good stability, fast response (<2 min), distinct color change, and high selectivity and sensitivity (LOD = 5.128 μM) to H 2 S in the HEPES solution, demonstrating its potential application for H 2 S detection under various solution conditions.