Piezoelectric immunosensor based on antibody recognition of immobilized open-tissue transglutaminase: An innovative perspective on diagnostic devices for celiac disease

A piezoelectric immunosensor was developed for the first time for direct detection of anti-tissue transglutaminase antibodies (anti-tTG), very specific biomarkers for reliable and early diagnosis of celiac disease. Since the inflammation processes associated to the pathology's occurrence involve tTG structural changes from closed to open conformation as well the extended structure has been demonstrated to have higher diagnostic accuracy if compared with closed conformation, the new strategy undertaken in this study was based on the immobilization of tTG enzyme in its open conformation as receptor on immunosensor surface. Ten nm-sized gold nanoparticles conjugated with secondary antibodies were exploited for signal amplification. Liquid phase detection conditions using a laminar flow cell were properly selected in order to have a good signal stability both in dynamic and in static modes. Optimization of the operating conditions, by experimental design on mouse anti-tTG antibodies in serum, allowed us to obtain a model for the realization of a reliable piezoelectric immunosensor with high potential as diagnostic device for the determination of human autoantibodies of celiac patients.