Ab initio simulations of doped single-walled carbon nanotube sensors

►Ab initio calculations used to study O-doped and N-doped SWNT within the framework of the DFT. ► We introduced new type of gas sensor that can detect the presence of H2, Cl2, NO, and CO molecules. ►Band-gap narrowing occurs when the nanotube is doped with oxygen or nitrogen atoms. ► We proposed a new methodology of designing reliable, sensitive, and selective nanotube sensors.