Ligand-bridged nanoassemblies boost the peroxidase-mimicking activity of gold nanoclusters

Rational design of nanozymes with enhanced catalytic efficiency remains a central challenge in the development of artificial enzymes. Herein, we report the construction of ultrasmall gold nanocluster-based nanoassemblies (Dp-AuNCs@Fe 2+ ) through the coordination of Fe 2+ ions by a dopa-containing peptidomimetic ligand (DpCDp). This nanoarchitecture simultaneously integrates catalytically active gold cores and redox-active Fe 2+ centers, bridged by DpCDp to facilitate directional electron transfer. Comprehensive spectroscopic and kinetic analyses reveal that DpCDp promotes efficient charge migration from the Au core to surface-bound Fe 2+ , significantly enhancing H 2 O 2 -mediated peroxidase-like activity. Compared to bare Dp-AuNCs, Dp-AuNCs@Fe 2+ display a 4.3-fold improvement in detection sensitivity, a 6.7-fold increase in catalytic efficiency, and markedly stronger hydroxyl radical generation. Mechanistically, this activity stems from a synergistic triad: direct H 2 O 2 oxidation at gold surfaces, radical generation at Fe 2+ sites, and DpCDp-facilitated electron shuttling. This work presents a robust strategy for nanozyme enhancement via electronic and structural co-engineering, offering valuable insights for the future design of bioinspired catalytic systems. We report a robust and modular strategy to construct peroxidase-mimicking nanoassemblies by leveraging catechol-containing peptidomimetic ligands (DpCDp) to bridge gold nanoclusters (AuNCs) via Fe 2+ coordination. The resulting Dp-AuNCs@Fe 2+ assemblies exhibit significantly enhanced catalytic performance, owing to Fe 2+ -induced interfacial electron redistribution and intrinsic Fenton-like activity.