Four-terminal graphene nanoribbon sensor devices: In-silico design and characterization

We present a low-voltage 4-terminal graphene nanoribbon (GNR) device for the detection and measurement of low concentration analytes. The designed device uses a low-bandgap, near-metallic channel whose electronic transport properties aim to resemble the characteristics of commercially-available, large-area graphene devices. The device is demonstrated in the detection of uridine diphosphate glucose (UDP-glucose), an intermediate reactant in the synthesis of sucrose and an indirect/proportional indicator of sucrose production within a plant's cell cytoplasm. The channel's surface is non-covalently functionalized with a self-assembled monolayer (SAM) of 1-pyrenebutyric acid (PyBA) that allows binding of UDP-glucose molecules on the carboxylic end, thus modifying the conductivity of the device's adsorption channel and enabling single-molecule detection via a 4-terminal monolayer configuration.