Fabrication of graphene-based back-gated field effect transistor for cortisol detection

In this work, we fabricated graphene-based back-gated field effect transistor for biosensor applications. Back-gated field effect transistors were fabricated on p-type silicon substrate with 300nm thermally grown silicon oxide layer. The effect of different drops of graphene which were one drop, two drops and three drops were characterized using Scanning Electron Microscope (SEM) and Keithley 4200 Semiconductor Parametric Analyzer (SPA) to study the effect of different drops of graphene towards the conductivity of the BGFET. The fabricated device was then functionalized with linker molecules and immobilized with antibody for selective sensing of cortisol biomarker. The changes at each modification steps were studied through the changes in electrical conductivity of the device