Abstract
Various methodologies have been reported in the literature for the qualitative and quantitative monitoring of mycotoxins in food and feed samples. Based on their enhanced specificity, selectivity and versatility, bio-affinity assays have inspired many researchers to develop sensors by exploring bio-recognition phenomena. However, a significant problem in the fabrication of these devices is that most of the biomolecules do not generate an easily measurable signal upon binding to the target analytes, and signal-generating labels are required to perform the measurements. In this context, aptamers have been emerged as a potential and attractive bio-recognition element to design label-free aptasensors for various target analytes. Contrary to other bioreceptor-based approaches, the aptamer-based assays rely on antigen binding-induced conformational changes or oligomerization states rather than binding-assisted changes in adsorbed mass or charge. This review will focus on current designs in label-free conformational switchable design strategies, with a particular focus on applications in the detection of mycotoxins.
Highlights
Biosensors have emerged as a cheap and quick alternative to traditional chromatographic methods in the analytical assayfield
Aptamers and aptasensors reported in the literature have been mostly designed for ochratoxin A (OTA), aflatoxins B1, B2 and M1 (AFB1, AFB2 and AFM1), fumonisin B1 (FB1) and zearalenone (ZEA)
Two aptamers have been selected by different research groups for the carcinogenic mycotoxin fumonisin B1 [93,94]
Summary
Biosensors have emerged as a cheap and quick alternative to traditional chromatographic methods in the analytical assayfield. As aptamers and antigens are chemically inert, a label such as an enzyme is required to generate an electrochemical signal [6,7,8] These developed methods are very sensitive, there are several challenges in the construction of labeled aptasensors. Label-Free technology is based on the measurement of the generated signal obtained after the surface change induced by the analyte It offers direct information about the interaction of the target with the sensing element by measuring changes on physical properties such as mass, refractive index, or electrical resistivity produced by this binding [22]. In addition to methods based on solid supports, label-free assays can be performed directly in solution and are mostly coupled to optical detection.The best example of these assays are sensors based on the switchable structure of aptamers, aptamer DNAzymes and/or chemical of physical properties of nanoparticles [24]. Label-Free detection offer new opportunities to food safety field due to their numerous advantages such as: high sensitivity, simplicity, and possible miniaturization and portability, which are indispensable for point of care applications [22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
