During the last 15 years, 2D materials have revolutionized the field of materials science. Moreover, because of their highest surface-to-volume ratio and properties extremely susceptible to their interaction with the local environment they became powerful active components for the development the high-performance chemical sensors. By combining different 2D materials to form van der Waals heterostructures (VDWHs) it is possible to overcome the drawback of individual materials (such as inertness and zero-bandgap of pristine graphene and less environmental stability of transition metal dichalcogenides). Meanwhile, VDWHs possess unprecedented and fascinating properties arising from the intimate interaction between the components, which can yield superior sensitivities, higher selectivity, and stability when employed to detect gases, biomolecules, and other organic/inorganic molecules. Herein, the latest developments and advances in the field of chemical sensors based on VDWH of 2D materials, with specific insight into the sensing mechanisms, are reviewed and future directions, challenges, and opportunities for the development of the next generation of (bio)chemical sensors with potential impact in environmental sciences and biomedical applications, and more specifically in (bio)chemical defense, industrial safety, food, and environmental surveillance, and medical (early) diagnostics, are discussed.
