Question

what to write as an abstract about the detection of Ochratoxin A using aptamer-based lateral flow strip biosensor

Answer 1

Ochratoxin A (OTA) is a type of mycotoxin generated from the metabolism of Aspergillus and Penicillium, and is extremely toxic to humans, livestock, and poultry. Ochratoxin A identified as a contaminant in grains and wine throughout the world, and convenient, rapid and sensitive detection methods for OTA have been a long-felt need for food safety monitoring. OTA-producing microorganisms are ubiquitous in nature and OTA itself is difficult to degrade, OTA can also contaminate a range of agricultural products, including grains, beans, nuts, and wheat.  So a new competitive format based lateral flow strip fluorescent aptasensor for one-step determination of OTA in corn samples is developed.

Aptamers are single-stranded oligonucleotides selected from a DNA or RNA library in vitro by a standard process named systematic evolution of ligands by exponential enrichment (SELEX), which can bind to target molecules with high affinity and specificity by folding into specific three-dimensional structures. Lateral flow strip biosensor (LFB) based aptamer has been employed with unique characteristics of sensitivity, specificity and operation simplicity.

The principle of LFB is based on the competitive reaction between cDNA (test line) and Cy5-labeled aptamer, indicating that the fluorescence intensity ratio of the T line to C line is  inversely proportional to the OTA concentration in the samples. When the sample solution without OTA was dropped onto the sample pad, the mixture migrated to the test zone with capillary dynamic and Cy5-labeled aptamer is captured largely by cDNA to form a stable double helix, resulting in strong fluorescence intensities in the control and test zones, respectively.In the presence of OTA, however, OTA would combine with the aptamer probe, reducing the amount of Cy5-labeled aptamer, which could hybridize to cDNA on the test line, and therefore the fluorescence intensity became weaker.the more aptamer OTA complexes existed in the solution, the less free Cy5-labeled aptamer would be captured on the test line. And no matter whether OTA was present in the detection solution, aptamer probes would definitely hybridize with probe 2 on the control line, ensuring the detection validity.

The detection process could be accomplished within 20 min. The Lateral flow strip biosensor strip can be applicable to any rapid onsite detection of OTA in corn samples, and for rapid qualitative and quantitative screening of OTA contamination in grain and foodstuff samples.