pH-Switchable Multi-Enzyme-Mimicking via Liquid Metal Nanozyme

Area of Science:

• Materials Science
• Nanotechnology
• Biochemistry

Background:

• Nanozymes exhibit pH-dependent catalytic activity, limiting their applications.
• Liquid metals (LM) offer unique electronic and morphological properties for advanced material design.

Purpose of the Study:

• To design a magnetic liquid metal-buffered iron oxide nanozyme (FeOₓ@EGaIn) with pH-switchable enzymatic activities.
• To investigate the role of LM as an electron transport substrate in enhancing nanozyme catalytic efficiency.
• To explore the potential of this nanozyme in biosensing and biomedical applications.

Main Methods:

• Fabrication of a magnetic FeOₓ@EGaIn nanozyme.
• Characterization of pH-dependent enzymatic activities (peroxidase and catalase).
• Evaluation of magnetic recovery and application in colorimetric biosensing.

Main Results:

• FeOₓ@EGaIn demonstrated excellent peroxidase (POD) activity in acidic conditions (K_m = 2.12 mM, v_max = 1.96 × 10⁻⁶ M s⁻¹).
• The nanozyme switched to catalase (CAT) activity under neutral to alkaline conditions with high stability.
• Magnetic responsiveness enabled convenient catalyst recovery.

Conclusions:

• The developed liquid metal nanozyme exhibits tunable, pH-switchable enzymatic activities, regulated by its electronic microenvironment.
• This offers new possibilities for dynamic biosensing of pH-responsive biomolecules.
• Expands applications of liquid metals in catalysis, sensing, and biomedicine.