Nanowires, Nanorods and Nanotubes are well-known monodimensional (1D) nanostructures. They exhibit a very high surface to volume ratio as well as unique magnetic and electrical properties which make them ideal candidates for new and innovative sensing devices. One of the key aspects in new biosensor developments is the alignment of monodimensional nanostructures that can be obtained by employing Langmuir Blodgett techniques as well as electrical and magnetic external fields. There recently have been many successful applications of 1D nanostructures in high performance sensors, such as field biomedical sensors that are able to detect very low concentrations of DNA and novel gas sensors for the detection of ultra-low concentration of toxic gases. The well-improved sensors employing 1D-nanostructures have a profound impact on healthcare and safety, thereby playing a more and more important role in the near future.