Hybridized Polyoxometalate-Based Metal-Organic Framework with Ketjenblack for the Nonenzymatic Detection of H 2 O 2 .

The rational design and development of efficient and affordable enzyme-free electrocatalysts for electrochemical detection are of great significance for the large-scale applications of sensor materials, and have aroused increasing research interest. Herein, we report that a typical polyoxometalate (POM)-based metal-organic framework (NENU5) that was hybridized with ketjenblack (KB) was a highly efficient electrochemical catalyst that could be used for the highly sensitive nonenzymatic detection of H2 O2 . The composite catalyst exhibited superb electrochemical detection performance towards H2 O2 , including a broad linear range from 10-50 mm, a low detection limit of 1.03 μm, and a high sensitivity of 33.77 μA mm-1 , as well as excellent selectivity and stability. These excellent electrocatalytic properties should be attributed to the unique redox activity of the POM, the high specific surface area of the metal-organic framework (MOF), the strong conductivity of KB, and the synergistic effects of the multiple components in the composites during the electrolysis of H2 O2 . This work provides a new pathway for the exploration of nonenzymatic electrochemical sensors.