Dimensionality Engineering of Single-Atom Nanozyme for Efficient Peroxidase-Mimicking

In nature, enzymatic reactions occurin well-functioning catalyticpockets, where substrates bind and react by properly arranging thecatalytic sites and amino acids in a three-dimensional (3D) space.Single-atom nanozymes (SAzymes) are a new type of nanozymes with activesites similar to those of natural metalloenzymes. However, the catalyticcenters in current SAzymes are two-dimensional (2D) architecturesand the lack of collaborative substrate-binding features limits theircatalytic activity. Herein, we report a dimensionality engineeringstrategy to convert conventional 2D Fe-N-4 centers into 3Dstructures by integrating oxidized sulfur functionalities onto thecarbon plane. Our results suggest that oxidized sulfur functionalitiescould serve as binding sites for assisting substrate orientation andfacilitating the desorption of H2O, resulting in an outstandingspecific activity of up to 119.77 U mg(-1), whichis 6.8 times higher than that of conventional FeN4C SAzymes.This study paves the way for the rational design of highly activesingle-atom nanozymes.