An aptamer-based chromatographic strip assay for sensitive toxin semi-quantitative detection

Area of Science:

• Analytical Chemistry
• Biosensing Technology
• Food Safety

Background:

• Ochratoxin A (OA) is a prevalent mycotoxin posing significant health risks.
• Current detection methods for OA can be time-consuming and require laboratory settings.
• Development of rapid, sensitive, and on-site detection tools for OA is crucial.

Purpose of the Study:

• To develop and validate an aptamer-based chromatographic strip assay for the rapid detection of ochratoxin A.
• To compare the sensitivity and efficiency of the aptamer-based strip assay with conventional antibody-based methods.
• To assess the potential of the assay for on-site, real-time toxin screening.

Main Methods:

• A competitive assay format was designed utilizing aptamers that bind to ochratoxin A.
• DNA probes were employed in conjunction with aptamers for signal generation in a strip assay format.
• The assay principle relies on the competition between ochratoxin A and DNA probes for aptamer binding.
• Visual and reader-based detection methods were utilized to determine the limit of detection (LOD).

Main Results:

• The aptamer-based strip assay demonstrated superior sensitivity compared to traditional antibody-based strips.
• A visual limit of detection (LOD) of 1 ng/mL was achieved for qualitative detection.
• Semi-quantitative detection yielded an LOD as low as 0.18 ng/mL when using a scanning reader.
• Recovery rates for test samples ranged effectively from 96% to 110%.
• Assay completion time was less than 10 minutes, highlighting its rapid nature.

Conclusions:

• The developed aptamer-based strip assay is a highly sensitive and rapid method for ochratoxin A detection.
• The assay's speed and on-site applicability make it a valuable tool for food safety monitoring.
• This technology offers a promising alternative to conventional methods for toxin analysis.