CONICET | Buscador de Institutos y Recursos Humanos

Celiac disease is caused by exposure to foods containing gluten in genetically susceptible individuals. The only effective therapy is strict dietary abstinence from foods containing gluten. Following this diet is difficult for celiac patients, due to variations in food labeling, misinformation, and cross-contamination. Consequently, it is relevant to develop a sensitive and specific method to quantify gluten trough detection of gliadin in food destined to celiac patients. In this sense, the development of a paper based electrochemical immunosensor represents an attractive strategy for gliadin quantification in foods samples. The designed system consists of a paper immunoaffinity support in which hydrophobic barriers generated by wax printing delimited de reaction area where the covalent immobilization of antigliadin antibodies was performed. This support was combined with a screen-printed carbon electrode modified with carbon nanofibers electrochemically reduced for the amperometric detection of gliadin. Carbon nanofibers increases of surface area and the electrical conductivity which provide high sensitivity making them extremely suitable for electrode modification. The modified electrode surface was characterized by scanning electron microscopy and cyclic voltammetry. The electrochemical device was applied to determine the gliadin concentration in different flour samples. The calculated limit of detection for the device and Elisa were 0.11 ppb and 1.5 ppm respectively and the coefficient of variation (CV) for determination of 20 ppb of gliadin was 4.11 %. The results show that the developed sensor represents a valuable contribution for gluten-free food control applications requiring a disposable device to perform fast, sensitive and selective determinations.