Dual-Active Centers Linked by Oxygen Transfer for Enhancing Proximity-Orientation Effect of Nanozyme

Abstract

Proximity-orientation effects (POE) are essential for enzymes, as the spatial arrangement and orientation of catalytic sites strongly influence substrate binding and enhance catalysis. However, nanozymes often face limitations due to weak POE arising from uniform catalytic interfaces. Herein, Co atoms are incorporated into the lattice of Pt-based nanozymes, exploiting differences in electron configuration and atomic radius between transition metals and noble metals. This integration induced lattice distortion formed new catalytic sites, and restricted the transport path, thereby enhancing the POE. Such transition metal-doped alloy nanozyme (TANzyme) can be functioned as a self-cascading nanozyme with artificial catalase-oxidase activity. Density functional theory calculations demonstrated that the Pt site selectively decomposed H₂O₂ into H₂O and O₂, while the Co site specifically adsorbed O₂ and conversed into superoxide anions, so an oxygen transfer path to connect dual-active centers not only increased the POE but also improved catalytic specificity. Additionally, by leveraging the efficient catalytic property of TANzyme, a visual origami-based sensing strategy is developed for the cascade detection of H₂O₂, nucleic acids, and marine toxins. This strategy highlighted the pivotal role of POE in enhancing the catalytic specificity of nanozymes, mimicking natural POE in enzymes, and providing a solution to design next-generation nanozymes.