Engineering hetero-structural iron nanozyme decorated liposome with a self-cascade catalysis performance

Area of Science:

• Biomaterials Science
• Nanotechnology
• Enzyme Mimics

Background:

• Metal-based enzyme mimics are crucial for fabricating heterogeneous biocomposites.
• Iron oxide nanoparticles (Fe3O4 NPs) offer a promising substitute for metallic enzymes.
• Overcoming limitations of peroxide-like enzymatic activity in physiological conditions is essential.

Purpose of the Study:

• To fabricate a soy phosphatidylcholine/Fe3O4@Ag/GOx (SFAG) biocomposite as a cascade enzyme.
• To investigate the peroxidase-like property of SFAG for glucose detection.
• To explore the synthesis mechanism using ultrasound and microfluidics.

Main Methods:

• Fabrication of SFAG biocomposite using ultrasound and microfluidic approach.
• Characterization of SFAG properties including absorption peak, size, and surface charge.
• Assay of peroxidase-like activity by catalyzing TMB with H2O2.
• Determination of Michaelis-Menten parameters (Km, Vmax) for H2O2.
• Application in glucose determination in PBS and synthetic blood.

Main Results:

• SFAG exhibits a characteristic absorption peak at 652 nm, size of 55 μm, and surface charge of -32.93 ± 2.58 mV.
• Peroxidase-like activity was confirmed under physiological conditions, with enhanced activity at pH 5.8, 7.4, and 8.0.
• Michaelis-Menten parameters for H2O2 were determined as Km = 1.914 mM and Vmax = 1.429 × 10^-7 M s^-1.
• Successful determination of glucose in PBS and synthetic blood with excellent sensitivity and stability.

Conclusions:

• The SFAG biocomposite demonstrates effective peroxidase-like activity and catalytic performance.
• The developed platform shows great potential as a cascade metallic enzyme in chemokinetic applications.
• SFAG offers a stable and sensitive method for glucose determination.