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

摘要

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 functionalized 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 modified onto the graphene surface. And then, plots of the conductance change and the target proteins concentration were fitted by the Langmuir adsorption isotherm. These results indicate that the Fab-modified G-FETs have high potentials for high sensitive biological sensors using antigen-antibody reactions.