Single-Walled Carbon Nanotubes as a Chemical Sensor for SO₂ Detection

Single-walled carbon nanotubes (SWNTs) are Introduced as a chemical sensor for the detection of sulfur dioxide (SO2) molecules. For a single bundle of SWNTs, current-voltage (I-V) curves were measured for a series of different temperatures under adsorption of SO2molecules. The I-V characteristics for a "MAT"-type thin film SWNTs, with respect to the amount of SO2adsorbed, were measured at room temperature and compared directly with O2adsorption. The change in current upon the adsorption of SO2is distinctly higher than that of O2, and is also reversible for adsorption and successive evacuation. Thus, the results strongly suggested that a thin film of SWNTs can be used as a chemical sensor in the nanometer scale devices.