Integrated nanotube sensors are adapted for detecting various chemical and biological molecules. In one implementation, nanotube sensor arrays are formed as nano-electronic noses capable of such detection, and can be implemented in devices including carbon nanotube-based electronic noses and biochips. Various implementations of the present invention are also directed to nanoscience and nanotechnology applications, such as medical, military and biological applications. In a more particular implementation, nanotubes are produced on full-scale wafers and functionalized. In another more particular implementation, functionalized nanotubes are integrated into addressable devices. With these approaches, various aspects of the present invention have been found to be useful in sensor applications having small size, high density and extreme sensitivity. Such sensor applications are applicable to many aspects of society, and can be implemented for making human lives more safe, secure and healthy.