Porphyrinic MOF Film for Multifaceted Electrochemical Sensing

Electrochemical sensors are indispensable in clinical diagnosis, biochemical detection and environmental monitoring, thanks to their ability to detect analytes in real-time with direct electronic readout. However, electrochemical sensors are challenged by sensitivity—the need to detect low concentrations, and selectivity—to detect specific analytes in multicomponent systems. Herein, a porphyrinic metal-organic framework (PP-MOF), Mn-PCN-222 is deposited on a conductive indium tin oxide (ITO) surface. It affords Mn-PCN-222/ITO, a versatile voltammetric sensor able to detect redox-active analytes such as inorganic ions, organic hazardous substances and pollutants, including nitroaromatics, phenolic and quinone-hydroquinone toxins, heavy metal ions, biological species, as well as azo dyes. As a working electrode, the high surface area of Mn-PCN-222/ITO enables high currents, and therefore leverages highly sensitive analysis. The metalloporphyrin centre facilitates analyte-specific redox catalysis to simultaneously detect more than one analyte in binary and ternary systems allowing for detection of a wide array of trace pollutants under real-world conditions, most with high sensitivity.