Enzyme-linked immunosorbent assays are currently the most popular methods to quantify gluten in foods. Unfortunately, the antibodies used as specific receptors in such methods are not compatible with the usual solvents for the extraction of gluten proteins. In consequence, commercial tests require a high dilution of the sample after the extraction, increasing the limit of quantification and decreasing convenience. In this work, we have rationally truncated an aptamer capable of recognizing gliadin in a deep eutectic solvent (DES). The truncated aptamer is a 19-nucleotides-long DNA that minimizes self-hybridization, allowing the development of an electrochemical sandwich-based sensor for the quantification of gluten in the DES ethaline. The sensor incorporates two identical biotin-labeled truncated aptamers, one of which is immobilized on a carbon screen-printed electrode and the other reports the binding of gliadin after incubation in streptavidin-peroxidase. This sensor can detect gliadin in DES, with a dynamic range between 1 and 100 μg/L and an intra-assay coefficient of variation of 11%. This analytical performance allows the quantification of 20 μg of gluten/kg of food when 1 g of food is extracted with 10 mL of ethaline. We demonstrate the ability of this method to achieve the measurement of gluten in food samples, after the extraction with pure ethaline. The assay is useful for the analysis of residual gluten levels in foods, thus facilitating the evaluation of any potential health risk associated with the consumption of such food by people with celiac disease or other gluten-related disorders.

酶联免疫吸附测定法是目前最流行的定量食品中麸质的方法。不幸的是，在这种方法中用作特异性受体的抗体与提取面筋蛋白的常用溶剂不兼容。因此，商业测试需要在提取后对样品进行高度稀释，从而增加了定量极限，并降低了便利性。在这项工作中，我们已经合理地截断了能够识别深共熔溶剂（DES）中的麦醇溶蛋白的适体。截短的适体是19个核苷酸长的DNA，可最大程度减少自身杂交，从而允许开发基于电化学夹心的传感器，用于定量DES乙醇中的面筋。该传感器包含两个相同的生物素标记的截短适体，其中一个固定在碳丝网印刷的电极上，另一个报告在链霉亲和素过氧化物酶中孵育后麦醇溶蛋白的结合。该传感器可以检测DES中的麦醇溶蛋白，动态范围为1至100μg/ L，测定内变异系数为11％。当用10 mL乙胺提取1 g食品时，这种分析性能可定量测定20 kg g面筋/ kg食品。我们证明了用纯乙胺提取后，该方法能够实现食品样品中麸质测量的能力。该测定法可用于分析食品中残留的麸质水平，从而有助于评估与腹腔疾病或其他与麸质相关的疾病的人食用此类食品所带来的任何潜在健康风险。