Bioinspired Design of Fe³⁺ -Doped Mesoporous Carbon Nanospheres for Enhanced Nanozyme Activity

Nanozymes have received considerable attention as alternatives of natural enzymes. However, the catalytic activity of nanozymes is often lower than that of natural enzymes, which largely limits their applications. Current methods utilized to improve the catalytic efficiency and substrate selectivity of a nanozyme usually have some inherent drawbacks. Herein, a biomimetic strategy was developed to design Fe³⁺ -doped mesoporous carbon nanospheres (Fe³⁺ -MCNs) as a horseradish peroxidase (HRP) mimic to realize the structure and function mimicking of natural HRP. In this system, Fe³⁺ ions could act as catalytic centers and carboxyl-modified mesoporous carbon nanospheres (MCNs-COOH) could be used to bind with substrates. As a result, Fe³⁺ -MCNs showed higher enzymatic activity than that of Fe₃ O₄ nanoparticles. Therefore, this strategy can contribute to the development of nanozymes and further understanding of the complicated enzymatic reactions in natural and biological systems.