Food adulteration is a global concern, and developing countries are associated with having a higher risk of it due to a lack of monitoring and policies. Diarrhea, nausea, allergic reactions, diabetes, cardiovascular disease, etc., are frequently observed illnesses upon the consumption of adulterated food. Therefore, the detection of adulteration in food is essential to ensure the safety of the food we consume. Currently, chromatography and spectrometry are widely used analytical techniques. Protein- and DNA-based techniques are also in practice. More recently, authenticity has been identified by detecting the content of the microRNA (miRNA) in foods. Some studies have shown that some miRNA in plants can be directly absorbed by the human body through the digestive tract, thus regulating the expression of related target genes, and then affect a series of physiological functions of the human body. Using duck as mutton is the main means of adulterating mutton kebabs at present. Mutton contains miR-192 and miR-486.

The traditional methods used for detecting microRNA are Northern blotting, qRT-PCR, in situ hybridization, and so on, but these techniques are complex and tedious, and require expensive instruments and well-trained personnel. In this report, we developed a gold nanoparticle (AuNP)-based lateral flow nucleic acid biosensor (LFNAB) for the visual detection of miR-122. This method has the advantages of a short detection time, high sensitivity, and simple operation. When the sample solution contains miR-122, T and C lines are displayed in LFNAB, while when there is no miR- 122 in the sample solution, only C lines are displayed in LFNAB. Currently, we can detect 10 pM miR-122 in 15 min without complex instrumentation. The reported method offers great promise for applying LFNAB in food adulteration.

Keywords: food adulteration; microRNA; lateral flow biosensor