Nanozyme-Linked Immunosorbent Assays: A Kinetic Perspective.

Area of Science:

• Biochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Nanozymes with peroxidase-like (POD) activity are emerging as effective substitutes for horseradish peroxidase in various bioassays.
• Nanozyme-linked immunosorbent assays (NLISA) leverage nanozymes within the established ELISA framework for detecting diverse analytes.
• Current NLISA protocols often fail to account for the distinct catalytic mechanisms of nanozymes versus traditional enzymes, leading to suboptimal performance.

Purpose of the Study:

• To investigate the impact of nanozyme properties, specifically shell thickness, on Michaelis-Menten kinetics.
• To explore the stability of nanozyme POD activity under extreme conditions, particularly ultralow pH.
• To develop optimized NLISA protocols by considering the unique catalytic characteristics of nanozymes.

Main Methods:

• Utilized core@shell gold-platinum (Au@Pt) and gold-palladium (Au@Pd) nanozymes with POD-like activity.
• Characterized Michaelis-Menten constants in relation to varying shell thicknesses.
• Assessed nanozyme activity stability at ultralow pH values (down to -0.56).

Main Results:

• Demonstrated significant variations in Michaelis-Menten constants influenced by nanozyme shell thickness.
• Reported unprecedented stability of POD-like activity at ultralow pH.
• Identified new strategies for effectively terminating catalytic reactions based on pH stability.

Conclusions:

• Understanding the unique catalytic properties of nanozymes is crucial for optimizing NLISA protocols.
• Optimized NLISA protocols utilizing nanozymes can achieve up to a tenfold increase in sensitivity.
• The developed strategies minimize background noise, leading to more reliable assay results.