Proposal of an Embedded Nanogap Biosensor by a Graphene Nanoribbon Field-Effect Transistor for Biological Samples Detection

Herein, it is examined how a graphene nanoribbon field-effect transistor (GNRFET) can be a useful nanoscale device, along with how to use an embedded nanogap inside a top gate oxide to form a biosensor. A streptavidin-biotin binding system with the dielectric constant of 2.1 is considered as a biological test sample for detection. Introducing the biological sample to the nanogap without a buffer solution modifies the electrostatic modulation in the graphene sheet, resulting in a change in the drain current. The order of change in the drain current is considered a criterion to measure the sensitivity of the proposed biosensor. A detailed investigation and discussion of the biasing conditions during the detection process reveal the optimal bias for the proposed biosensor to achieve a greater sensitivity, all while maintaining a desirable electrical performance.