Enhancing resolution in DNA staining dye-based label-free visual fluorescence aptasensor: Strategy for eliminating...

Area of Science:

• Biosensing and Nanomaterials
• Development of advanced analytical techniques for food safety.

Background:

• Aflatoxin B1 (AFB1) poses significant health risks, necessitating sensitive and rapid detection methods.
• Existing detection methods often lack sensitivity, speed, or simplicity for field applications.
• Two-dimensional (2D) nanomaterials offer unique properties for biosensor development.

Purpose of the Study:

• To develop a highly sensitive, label-free fluorescence aptasensor for AFB1 detection.
• To optimize the use of 2D nanomaterials for enhanced sensor performance.
• To enable rapid and visually intuitive AFB1 detection.

Main Methods:

• Designed a label-free fluorescence aptasensor incorporating a novel dicationic fluorophore (VLM) and complementary DNA (cDNA).
• Evaluated various 2D nanomaterials (GO, MXene, MoS2) for their quenching efficiency of background fluorescence.
• Utilized MoS2 nanosheets to achieve near-zero background signal and binding-induced turn-on fluorescence upon AFB1 detection.

Main Results:

• The MoS2-based aptasensor demonstrated excellent linearity for AFB1 detection from 2-3000 ng/mL, with a low limit of detection (LOD) of 0.006 ng/mL.
• Smartphone-based visual detection achieved linearity within the same range and an LOD of 0.197 ng/mL.
• The aptasensor provided rapid sample-to-answer results in just 74 minutes.

Conclusions:

• The developed label-free fluorescence aptasensor offers a highly sensitive and rapid method for AFB1 detection.
• The integration of MoS2 nanosheets significantly enhances sensor performance by minimizing background noise.
• This approach holds great potential for on-site, visual, and user-friendly food safety monitoring.