A simple aptamer-based fluorescent aflatoxin B1 sensor using humic acid as quencher

Area of Science:

• Analytical Chemistry
• Biotechnology
• Environmental Science

Background:

• Aflatoxin B1 (AFB1) is a toxic mycotoxin posing significant health risks.
• Accurate and sensitive detection methods for AFB1 are crucial for food safety and public health.
• Existing detection methods may lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a novel, sensitive, and fluorometric aptamer-based assay for the detection of aflatoxin B1 (AFB1).
• To utilize aptamer-modified carbon dots (DNA-CDs) and humic acid (HAs) for a fluorescence quenching-based detection system.

Main Methods:

• Synthesis of DNA-CDs as fluorescence probes.
• Utilizing humic acid (HAs) as a fluorescence quencher for DNA-CDs via adsorption.
• Developing a fluorescence restoration mechanism upon AFB1 binding to detach DNA-CDs from HAs.

Main Results:

• Humic acid effectively quenched the blue fluorescence of DNA-CDs through adsorption, likely via π interactions.
• The assay demonstrated fluorescence restoration in the presence of AFB1, indicating successful detection.
• Optimized conditions yielded a linear response for AFB1 concentrations from 0.1-0.8 ng/mL.
• A low limit of detection (LOD) of 70 pg/mL for AFB1 was achieved.

Conclusions:

• The developed fluorometric aptamer-based assay provides a sensitive and efficient method for AFB1 detection.
• The DNA-CDs-HAs system offers a promising platform for developing rapid and reliable mycotoxin detection tools.
• This assay has potential applications in food safety monitoring and environmental analysis.