Devices and methods for Terahertz (THz) sensing/detection, imaging, spectroscopy, and communication are provided. A graphene-based field effect transistor (FET) can have a quality factor of greater than 400 and a responsivity of at least 400 Volts per Watt. A FET sensor can include a substrate, a gate disposed on the substrate, an insulation layer disposed on the gate and the substrate, a source terminal and a drain terminal disposed on the substrate, and a graphene layer disposed on the insulation layer.