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Coordination-Tuned Iridium Single-Atom Nanozymes Boost Multienzyme Activity for Colorimetric Sensing
Tao Li1, Xinyu Zhang2, Jiashan Xia1
1Chongqing Key Laboratory of Prevention and Treatment for Occupational Diseases and Poisoning, Chongqing Municipal Health Commission Key Laboratory for Emergency Poisoning Detection and Acute Care, The First Affiliated Hospital of Chongqing Medical and Pharmaceutical College, Chongqing, China.
Introducing asymmetric sulfur coordination in single-atom nanozymes (SAzymes) enhances their catalytic activity and enables multifunctional applications. This breakthrough in coordination engineering unlocks new possibilities for advanced enzyme-mimetic catalysts.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- Single-atom nanozymes (SAzymes) offer high efficiency but face challenges in activity and multifunctionality due to coordination environment limitations.
- Current SAzymes often have symmetric coordination, hindering fine-tuning of electronic structures and intrinsic catalytic ceilings.
Purpose of the Study:
- To engineer asymmetric coordination environments in iridium SAzymes for enhanced catalytic performance.
- To investigate the impact of sulfur incorporation on the electronic structure and catalytic activity of iridium SAzymes.
- To develop multifunctional SAzymes for sensing applications.
Main Methods:
- Preparation of iridium SAzymes with an asymmetric Ir-N3S1 coordination motif (Ir-S/N-C) by sulfur doping.
- Density functional theory (DFT) calculations to analyze electronic structure modulation and energy barriers.
- Evaluation of oxidase, peroxidase, and glutathione-oxidase-like activities.
- Construction and testing of a H2O2-free colorimetric sensing system.
Main Results:
- The asymmetric Ir-N3S1 coordination upshifted the d-band center and lowered the O2 activation barrier.
- Ir-S/N-C exhibited significantly enhanced oxidase and peroxidase activities, alongside emergent glutathione-oxidase functionality.
- A sensitive and selective H2O2-free colorimetric sensing system for antioxidants and pesticides was successfully developed.
Conclusions:
- Asymmetric sulfur coordination is a viable strategy for fine-tuning the electronic structure of single-atom sites in SAzymes.
- This approach leads to high-performance multifunctional SAzymes with integrated enzyme-like activities.
- The developed SAzymes show promise for sensitive and selective sensing in complex matrices.
