Accurately measuring exhaled nitric oxide (eNO) is still an unsolved problem. We report the fabrication of a novel nanotube-based gas sensor. The gas sensor consists of a gas-responsive multiwall vanadium oxide nanotube (VO X-NT) layer deposited on a ceramic chip with two Ag-Pd electrodes, a gas sensor signal collecting system and a computer data-processing system. The absorption of different gases in the VOX-NT layer changes the permittivity and conductivity of the material and consequently alters the voltage of the sensor. By measuring the voltage change of the sensor, different gas concentr...
