Molybdenum Oxide Nanosheet-Supported Ferrous Ion Artificial Peroxidase for Visual Colorimetric Detection of Triacetone Triperoxide

The traditional nanozymes have low atom/ions utilization efficiency and are easily influenced by the size, morphology as well as surface composition of nanomaterials. Herein, we report a template-free and valid approach to prepare ferrous ion (Fe2+) anchored onto the surface of MoO3 nanosheet (Fe2+/MoO3) through coordination interaction between Fe2+ and hydroxyl groups of MoO3. The resulting Fe2+/MoO3 shows the peroxidase-like activity, and it can be utilized for catalytic decomposition of hydrogen peroxide (H2O2) to generate hydroxyl radicals (·OH) that oxidizes various chromogenic substrates, generating distinct color change and strong ultraviolet-visible (UV-vis) absorption. The Fe2+/MoO3 peroxidase mimic exhibits a good thermal stability and works well at a high reaction temperature (95 °C), and has higher affinity for substrates than natural horseradish peroxidase. Theoretical calculation results imply that the strong electrostatic field from the polarization charges between Fe2+ and MoO3 nanosheet i...