6.1.3 Fragment-Modified Graphene FET for Highly Sensitive Detection of Antigen-Antibody Reaction

Shogo Okamoto, Yusuhide Ohno, Kenzo Maehashi, Koichi Inoue & Kazuhiko Matsumoto
For high-sensitive and specific protein sensing using graphene field-effect transistors (G-FETs), the antigen-binding fragment (Fab), which is a component of conventional antibody, was functionalised onto the graphene surface. Since the height of the Fab is approximately 3 nm, the antigen-antibody reaction is expected to occur inside the electrical-double layer in the buffer solution. After functionalization of Fab onto the G-FET, the transfer characteristics shifted in the positive gate-voltage direction, indicating that the Fab was successfully...