Bimetallic Cu/Zn Single-Atom Nanozyme with Superoxide Dismutase-Like Activity

Area of Science:

• Biomaterials Science
• Nanotechnology
• Enzyme Mimicry

Background:

• Superoxide ion (O^2•-) is a key radical species in biological systems.
• Superoxide dismutase (SOD) enzymes neutralize O^2•-, but natural enzymes have limitations.
• Traditional nano ceria (CeO₂) nanozymes for SOD mimicry face challenges like toxicity and specificity.

Purpose of the Study:

• To synthesize and characterize a single-atom nanozyme (SAN) with enhanced superoxide dismutase (SOD) mimicry.
• To evaluate the efficacy and selectivity of the Cu/Zn bimetallic SAN in neutralizing superoxide radicals.
• To assess the potential of the Cu/Zn-SAN as a safer and more effective alternative to existing nanozymes.

Main Methods:

• Synthesis of a Cu/Zn bimetallic single-atom nanozyme (SAN).
• Assessment of SOD-mimicking activity by measuring inhibition of Nitro-blue tetrazolium (NBT) photoreduction.
• Evaluation of selectivity by testing for oxidase and peroxidase-like activities.
• Testing performance in cigarette smoke extract to demonstrate practical relevance and safety.

Main Results:

• The Cu/Zn-SAN exhibited superior catalytic activity (7820 U mg^-1) compared to natural SOD (4264 U mg^-1).
• The SAN demonstrated high specificity for SOD activity, with no detectable oxidase or peroxidase activity.
• The material showed significant efficacy in neutralizing superoxide radicals in a complex matrix like cigarette smoke extract.

Conclusions:

• The developed Cu/Zn bimetallic SAN is a highly effective and selective SOD mimic.
• This SAN offers a promising alternative to traditional nanozymes, addressing issues of toxicity and specificity.
• Potential applications include therapeutic interventions for oxidative stress-related diseases and cosmetic anti-aging products.