Turn on and Ratiometric Luminescent Sensing of Hydrogen Sulfide Based on Metal Organic Frameworks.
The sensing of hydrogen sulfide (H2S) has become a long time challenging task. In this work, we developed a general strategy for sensing of H2S utilizing postsynthetic modification of a nano metal organic frameworks (MOF) UiO 66 (COOH)2 with Eu3+ and Cu2+ ions. The nano MOF Eu3+/Cu2+@UiO 66 (COOH)2 displays the characteristic Eu3+ sharp emissions and the broad ligand centered (LC) emission simultaneously. Because H2S can strongly increase the fluorescence of Eu3+ and quench the broad LC emission through its superior affinity for Cu2+ ions, the MOF Eu3+/Cu2+@UiO 66 (COOH)2 exhibits highly sensitive turn on sensing of H2S over other environmentally and biologically relevant species under physiological conditions. Furthermore, this approach for fluorescent turn on sensing of H2S is expected to extend to other water stable MOFs containing uncoordinated COOH.
ACS applied materials interfaces