Sensors have played a pivotal role in revolutionizing healthcare, manufacturing, monitoring, and various other everyday technologies. Nanosensors are devices designed at the nanoscale and can utilize various kinds of nanomaterials. These sophisticated devices operate at an intersection of nanotechnology, physics, and materials science and are capable of converting physical, chemical, or environmental stimuli into measurable signals which can be interpreted, with the resulting information used to monitor, understand, or modulate the target. Usually, as the nanosensors come into contact with the target, they detect any physical, chemical, or biological variable which is later transduced to a measurable signal depending on the type of nanomaterials used, later the signal is amplified and refined by filtering excess noise. The information generated is translated into a readable output depending on the type of nanosensor. Typically, nanosensors employ different transduction mechanisms to convert one form of energy including electric, optic, thermal, or mechanical -to another form of energy. Incorporating nanomaterials such as nanoparticles, nanowires, nanotubes, or quantum dots enhances the specificity and sensitivity of sensors, enabling precise measurement. Moreover, nanomaterials provide a high surface area to volume ratio, thereby amplifying the interactions between sensor and target.