Carbon is the most versatile element in the periodic table, owing to the type, strength, and number of bonds it can form with many different elements. The diversity of bonds and their corresponding geometries enable the existence of structural isomers, geometric isomers, and enantiomers. The properties of carbon are a direct consequence of the arrangement of electrons around the nucleus of the atom. There are six electrons in a carbon atom, shared evenly between the 1s, 2s, and 2p orbitals. Carbon in the solid phase can exist in three allotropic forms: graphite, diamond, and buckminsterfullerene. In 1990, at a carbon-carbon composites workshop, Rick Smalley proposed the existence of a tubular fullerene. University of Technology demonstrated the first molecular transistor using a carbon nanotube. Carbon nanotubes have been heavily explored for their use in gas, biological and chemical sensors because of their very small diameters and their unique property that all of the atoms are on the surface of the tube.