Multi-Subunit Nanozyme: A Functionally Programmed Ru Nanocluster-Installed Tannic Acid-Framed Hollow ZIF-8 Single...

Area of Science:

• Biomaterials Science
• Catalysis
• Nanotechnology

Background:

• Multi-subunit enzymes utilize distinct functional domains for efficient biocatalysis.
• Replicating multi-subunit enzyme complexity in nanozymes is an underexplored area crucial for advancing nanozyme technology.
• Architecting multiple functional subunits within a single nanozyme construct presents a significant challenge.

Purpose of the Study:

• To introduce a novel multi-subunit nanozyme concept by integrating catalytic and structural/regulatory subunits.
• To mimic the synergistic functions of multi-subunit enzymes using a rationally designed nanozyme.
• To investigate the catalytic activity and selectivity of the developed multi-subunit nanozyme.

Main Methods:

• Synthesized a multi-subunit nanozyme (Ru-H-ZIF-8) by immobilizing ruthenium nanoclusters (Ru-NCs) onto tannic acid (TA)-framed hollow ZIF-8 (H-ZIF-8).
• Utilized TA as a structural/regulatory subunit and Ru-NCs as a catalytic subunit.
• Investigated the nanozyme's catalytic performance, including substrate activation, oxidation, and oxygen reduction, supported by mechanistic studies.

Main Results:

• The Ru-H-ZIF-8 nanozyme demonstrated synergistic activity, activating o-aminophenol (OAP) via hydrogen bonding (TA subunit) and catalyzing oxidation via electron transfer (Ru-NCs subunit).
• Achieved high reaction rates and remarkable substrate class selectivity, surpassing individual components and typical non-selective oxidase mimetics.
• Successfully performed a four-electron oxygen reduction without generating partially reduced oxygen species (PROS), exhibiting enzyme-like specificity comparable to phenoxazinone synthase (PHS).

Conclusions:

• Established a new paradigm for functionally programmed multi-subunit nanozymes by integrating distinct subunits with specific roles.
• Demonstrated a dynamic, bioinspired catalytic system that effectively mimics multi-subunit enzymes.
• Advanced nanozyme technology by creating a sophisticated nanozyme with enzyme-like specificity and efficient biomimetic oxygen reduction capabilities.