Nanotechnology is concerned with the physical and chemical properties of materials at the nanoscale, which are often distinct from their bulk qualities. These phenomena can be exploited by nanosensors. In comparison to classically designed sensors with only decreased sensing elements and/or the transducer, important attributes and quality parameters of nanosensors can be improved. The characteristics of materials at nanoscales can be used to create sensors. The functional units in such devices will be nano entities, even if the material itself is not nano in size. When analyte molecules interact with nanomaterials, features such as a large surface to volume ratio and physical properties will be exploited to generate a signal. Several sensors of this type have been created.