Multi‐Subunit Nanozyme: A Functionally Programmed Ru Nanocluster‐Installed Tannic Acid‐Framed Hollow ZIF‐8 Single Construct Exhibits Subunit‐Specific Roles in Facilitating Remarkable Substrate Selective Catalysis

Multi-subunit enzymes are constituted with multiple domains defined for specific functions for efficient biocatalysis. Replicating complex features and functions of multi-subunit enzymes in nanozymes remains unexplored and warrants investigation to advance nanozyme technology. However, the formidable challenge is to architect multiple subunits in a single nanozyme construct. Herein, we introduce a new concept of multi-subunit nanozyme (Ru-H-ZIF-8) by installing Ru nanoclusters (Ru-NCs) as a catalytic subunit on a structural/regulatory subunit, tannic acid (TA)-framed hollow ZIF-8 (H-ZIF-8). These subunits in a single nanozyme construct perform defined yet synergistic roles for mimicking multi-subunit enzymes. The TA-bound Ru-H-ZIF-8 nanozyme activates o-aminophenol (OAP) via hydrogen bonding, while the Ru-NCs subunit facilitates electron transfer to catalyse oxidation, collectively exhibiting a high reaction rate with remarkable substrate class selectivity, which is otherwise difficult to achieve by individual components. This nanozyme class significantly differs from typical non-selective oxidase mimetics. The Ru-H-ZIF-8 nanozyme parallelly completes four-electron oxygen reduction without releasing partially reduced oxygen species (PROS), and enzyme-like specificity comparable only to phenoxazinone synthase (PHS). Supported by detailed mechanistic insights, our investigation establishes a new functionally programmed multi-subunit nanozyme, advancing nanozyme research by constructing a dynamic bioinspired catalytic system having multi-subunits with specific functions.