|Celiac disease is an immune-mediated disorder triggered by foods containing gluten, a mixture of storage proteins in wheat, barley, rye and possibly oat. To date, there is no effective cure, and the only effective treatment consists in a lifelong gluten-free diet. Foods bearing a gluten-free label must not exceed the level of 20 mg gluten per kg product (Codex Standard). A major hurdle in the gluten contents management is the sensitivity of the current available methods. Therefore, intensive efforts are being made to develop promising and user’s friendly method to monitor the gluten content in food samples at levels as low as possible. Current techniques for gluten analysis include ELISA and Mass spectrometry. Although these methods are accurate, but there are intricate and time consuming and also involve cumbersome laboratory procedure which making such approaches impractical. Biosensors are considered to be promising tools for monitoring gluten in the food. Biosensors are rapid, cost-effective, field-portable and high-sensitivity instruments. The latest of the biosensors for detection of gluten are aptasensors, which use aptamer as a reorganization element. aptamers are single-stranded oligonucleotides with high specific recognition capabilities toward a wide range of targets . They are isolated from a combinatorial DNA library by an in vitro process known as SELEX (Systematic Evolution of Ligands by EXponential enrichment) . Compared to antibody, aptamers possess outstanding features, such as high productivity, affinity, selectivity, stability, low cost, ease of labeling and lack of toxicity [3, 4].
Herein, we summarized recent advances in aptasensors developed for gluten detection in order to provide an understanding of its improvement and progress. Aptamers provide an ideal alternative for designing biosensors for fast and selective measurement of gluten in foods.The gluten aptasensores have been listed in Tables 1.
The gluten aptasensors were divided into electrochemical and PCR formats. Malvano and coworkers designed an impedimetric aptasensor to detect gluten. Resulting aptasensor could analysis gluten, in gluten and gluten-free food products, showing a good agreement with the results obtained with official R5 ELISA method . Similarly, Amaya and coworkers used electrochemical competitive enzyme-linked assay on magnetic particles for gluten detection. The designed aptasensor has been successfully evaluated by detection gluten in the soya and cake samples . They also developed another gluten aptasensor based on chronoamperometry. In this biosensing method, the target peptide immobilized onto streptavidin-coated magnetic beads in combination with a limited amount of biotin-aptamer in a competitive format, followed by streptavidin-peroxidase labelling of the aptamer that remains bound to the magnetic beads. The enzyme activity onto the beads, measured by chronoamperometry in disposable screen-printed electrodes, is inversely related to the target concentration in the test solution . The range of examples presented here demonstrates that the aptamers have high potential for using in biosensors for rapid, simple, and sensitive detection of gluten. Despite all developments in gluten aptasensors, there are not commercial products available. Therefore, future research efforts should be focused on use of these reports in construction commercial diagnostic tools.