Atom-pair engineering of single-atom nanozyme for boosting peroxidase-like activity.

Constructing atom-pair engineering and improving the activity of metal single-atom nanozyme (SAzyme) is significant but challenging. Herein, we design the atom-pair engineering of Zn-SA/CNCl SAzyme by simultaneously constructing Zn-N 4 sites as catalytic sites and Zn-N 4 Cl 1 sites as catalytic regulator. The Zn-N 4 Cl 1 catalytic regulators effectively boost the peroxidase-like activities of Zn-N 4 catalytic sites, resulting in a 346-fold, 1496-fold, and 133-fold increase in the maximal reaction velocity, the catalytic constant and the catalytic efficiency, compared to Zn-SA/CN SAzyme without the Zn-N 4 Cl 1 catalytic regulator. The Zn-SA/CNCl SAzyme with excellent peroxidase-like activity effectively inhibits tumor cell growth in vitro and in vivo. The density functional theory (DFT) calculations reveal that the Zn-N 4 Cl 1 catalytic regulators facilitate the adsorption of * H 2 O 2 and re-exposure of Zn-N 4 catalytic sites, and thus improve the reaction rate. This work provides a rational and effective strategy for improving the peroxidase-like activity of metal SAzyme by atom-pair engineering.