Chapter 9: The chapter discusses the new sensing opportunities provided by nanotechnologies. After a brief overview of the current status of nanotechnologies, it presents a review of existing types of nanosensors. The different options for fabrication are summarized before moving on to detailing some of their electrical and sensing features. Two of the challenges of nanosensors, reproducibility and reliability, are explained in depth. Finally, we discuss how to integrate nanosensors into IoT devices to carry out their deployments in the field.