Atomically precise metal nanoclusters (MNCs) with flexible peripheral ligands provide selective channels and unique electronic structures to the rigid metal core, showing great application potential in many fields such as biomimetic nanozymes. In this study, we developed cost-effective, low-toxicity, and water-soluble MNC based self-cascade antioxidants for enhanced reactive oxygen species clearance. Compared to Ag nanoparticles, the Ag