Iron Single-Atom Anchored on N-Doped Carbon Nanozymes for Chlorpyrifos Detection and Antibacterial Applications

The poor activity and specificity of nanozymes limit their applications in many fields owing to their low density of active sites, inhomogeneous atomic composition, and complex structure. To overcome these issues, a single iron-anchored carbon material, Fe/CN-800-A, with FeN2 sites has been fabricated, which exhibited exclusive oxidase-like activity. The mechanisms of N-coordination-number-regulated enzymatic activity and specificity of the composite were also explored to elaborate the working principle. The FeN2 sites in Fe/CN-800-A exhibited higher oxidase-like activity and specificity than the FeN4 sites in Fe/CN-700, owing to their lower energy barriers for O2 absorption and the decomposition of H2O2 into O2. These findings provide a theoretical basis for the rational design of nanozymes with high oxidase-like activity and specificity. The fabricated nanocomposites have commercial potential for effective chlorpyrifos detection and antibacterial applications due to their unique structural traits and high efficiency.