  Graphene-based terahertz (THz) devices have emerged as promising platforms
for a variety of applications, leveraging graphene's unique optoelectronic
properties. This review explores recent advancements in utilizing graphene in
THz technology, focusing on two main aspects: THz molecular sensing and THz
wave modulation. In molecular sensing, the environment-sensitive THz
transmission and emission properties of graphene are utilized for enabling
molecular adsorption detection and biomolecular sensing. This capability holds
significant potential, from the detection of pesticides to DNA at high
sensitivity and selectivity. In THz wave modulation, crucial for
next-generation wireless communication systems, graphene demonstrates
remarkable potential in absorption modulation when gated. Novel device
structures, spectroscopic systems, and metasurface architectures have enabled
enhanced absorption and wave modulation. Furthermore, techniques such as
spatial phase modulation and polarization manipulation have been explored. From
sensing to communication, graphene-based THz devices present a wide array of
opportunities for future research and development. Finally, advancements in
sensing techniques not only enhance biomolecular analysis but also contribute
to optimizing graphene's properties for communication by enabling efficient
modulation of electromagnetic waves. Conversely, developments in communication
strategies inform and enhance sensing capabilities, establishing a mutually
beneficial relationship.
