Real-Time Monitoring of Dissolved Oxygen with Inherent Oxygen-Sensitive Centers in Metal-Organic Frameworks

Despite that they are regarded as the ideal sensory platform, there are still no reports on luminescent metal organic frameworks (LMOFs) for dissolved oxygen (DO) measurement. Here, we reported the rational construction of a platinum(II) porphyrinic LMOF, PCN-224(Pt), as an novel porous matrix for the phosphorescent DO sensing with commercially available Pt(II) meso-tetra(4-carboxyphenyl)porphyrin as the bridging struts, oxygen-sensitive centers, and luminescent reporters. The newly developed probe featured excellent tolerance to harsh chemical environments, excellent photostability as well as pH-independent luminescence, rationalizing its suitability for DO sensing. Thanks to the homogeneous and well-isolated arrangement of the oxygen-accessible sites in the porous network, PCN-224(Pt) exhibited reversible phosphorescent response and excellent linear Stem-Volmer quenching behavior toward DO. A real-time analysis of DO during the process of enzyme-catalytic reaction exemplified its potentials in industrial and biological applications with oxygen involved.