Imitating SubstrateChannels on a Mesoporous SiO₂‑Confined Fe₁ Single-Atom Nanozyme for EnhancingPeroxidase-like Activity

Single-atom nanozymes (SAzymes) are an emerging class of artificial enzymes that integrate metal single atoms on nanostructured supports, combining high catalytic efficiency with enzyme-like functionality. However, most designs have overlooked the role of substrate channels, which are essential in natural enzymes for enhancing specificity, accelerating kinetics, and suppressing side reactions. Herein, we design a bioinspired Fe₁@ SAzyme by confining Fe₁ single atoms within mesoporous SiO₂ (m-SiO₂) to imitate the function of enzymatic substrate channels. The periodic mesopores of m-SiO₂ not only ensure uniform Fe₁ dispersion but also enhance substrate transport and shorten radical migration pathways, thereby significantly boosting the peroxidase-like activity to conventional Fe-based nanozymes. This work bridges heterogeneous and enzyme catalysis, offering a promising strategy for next-generation nanozyme development.