Abstract: This invention provides an assembly of novel nanotube devices that can be employed in a variety of applications. In particular, the nanotube devices of the present invention provide a new class of versatile chemical and biological sensors. The present invention describes methods for growing individual nanotubes in a controlled fashion and for manipulating and integrating the nanotubes into functional devices. It further provides methods for modifying the nanotubes such that their sensitivity to a wide range of chemical and biological species can be achieved.