Nanotubes and nanotube-based devices are implemented in a variety of applications. According to an example embodiment of the present invention, a nanotube is adapted to pass current between two conductive elements. In one implementation, each conductive element includes a catalyst material, wherein electrical connection is made to opposite ends of the nanotube at each of the catalyst portions. In one implementation, the electrical connection is used to detect an electrical characteristic of the nanotube, such as the response of the nanotube to exposure to one or more of a variety of materials. In another implementation, the nanotube is used for chemical and biological sensing. In still another implementation, a particular functionality is imparted to the nanotube using one or more of a variety of materials coupled to the nanotube, such as metal particles, biological particles and/or layers of the same.