An Underlap Channel-Embedded Field-Effect Transistor for Biosensor Application in Watery and Dry Environment

An underlap channel-embedded FET is proposed for electrical, label-free biosensor in both watery and dry environments, and current-voltage characteristics measured under each environment are compared. To investigate the effectiveness of the underlap device as a biosensor for both environments, antigen-antibody binding of an avian influenza (AI) is used. Antibody of AI binding on antigen-immobilized surface provides additional negative charge on underlap surface, and they give rise to channel potential increasing and result in drain current reduction. In this study, we have verified that the biosensor characteristics measured under dry environment is valid as much as they are valid for watery environment.