Fluorescence assay for aflatoxin B1 based on aptamer-binding triggered DNAzyme activity

Area of Science:

• Analytical Chemistry
• Biotechnology
• Food Safety

Background:

• Aflatoxin B1 (AFB1) is a prevalent mycotoxin in agricultural products, posing significant risks to human health.
• There is a critical need for simple and highly sensitive methods for AFB1 detection.
• Current detection methods may lack the required sensitivity or simplicity for widespread application.

Purpose of the Study:

• To develop a novel aptamer-based fluorescence assay for the sensitive and selective detection of AFB1.
• To utilize DNAzyme technology for signal generation and amplification in AFB1 detection.
• To establish a practical tool for analyzing AFB1 in complex sample matrices.

Main Methods:

• Design and redesign of DNA sequences incorporating an anti-AFB1 aptamer and an RNA-cleaving DNAzyme (10-23).
• Development of an assay where AFB1 binding to the aptamer releases the DNAzyme, restoring its catalytic activity.
• Utilizing a fluorophore and quencher-labeled substrate that is cleaved by the activated DNAzyme, leading to a fluorescence signal.

Main Results:

• The assay demonstrated a wide dynamic range for AFB1 detection, from 0.98 to 2000 nmol/L.
• A low detection limit of 0.98 nmol/L was achieved, indicating high sensitivity.
• The assay exhibited high selectivity and effectiveness in detecting AFB1 within complex sample matrices.

Conclusions:

• The developed aptamer-based fluorescence assay provides a simple, sensitive, and selective method for AFB1 detection.
• The use of DNAzyme for signal amplification enhances the assay's performance.
• This assay represents a valuable tool for routine analysis and monitoring of AFB1 in food safety applications.