Ultrasensitive aptamer-based protein assays based on one-dimensional core-shell nanozymes

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Natural enzymes in immunoassays face limitations in preparation and storage, hindering point-of-care applications.
• Nanozymes provide a stable and easily fabricated alternative, mimicking natural enzyme functions.
• One-dimensional Fe3O4@C core-shell nanostructures were synthesized for enhanced catalytic activity.

Purpose of the Study:

• To develop a sensitive and convenient diagnostic assay using nanozymes.
• To detect platelet-derived growth factor BB (PDGF-BB) with high sensitivity.
• To explore the potential of nanozyme-based assays for clinical diagnosis.

Main Methods:

• Fabrication of 1D Fe3O4@C core-shell nanostructures via a solvent-thermal method.
• Development of a nanozyme-linked aptamer sorbent assay (NLASA) using Fe3O4@C nanowires as catalytic labels.
• Colorimetric detection of PDGF-BB with and without G-quadruplex-hemin DNAzyme incorporation.

Main Results:

• Fe3O4@C nanocomposites exhibited excellent peroxidase-like activity.
• The NLASA demonstrated a detection limit of 10 fM for PDGF-BB, with a working range of 10 fM to 100 nM.
• Incorporation of G-quadruplex-hemin DNAzyme lowered the detection limit to 50 aM.
• Detection of PDGF-BB in 50% human serum achieved a limit of 100 fM.

Conclusions:

• The developed nanozyme-based assay is ultrasensitive, cost-effective, and easy to operate.
• This platform offers significant potential for protein detection in clinical diagnosis.
• Nanozymes are promising alternatives to natural enzymes for advanced diagnostic tools.