Flexible gas sensors with assembled carbon nanotube thin films for DMMP vapor detection

Flexible gas sensors with assembled single-walled carbon nanotube (SWNT) thin films were fabricated to detect the nerve agent stimulant dimethyl methylphosphonate (DMMP) vapors at room temperature and their response characteristics were extensively investigated. The sensors show excellent mechanical flexibility with only a 5.6% deviation in the magnitude of response when bent in a glass tube with radius of about 5 mm. It can detect DMMP vapor in concentration as low as 1 ppm, with more than 3.6% resistance change. The magnitude of response to DMMP vapor is 0.232 ± 0.007 ppm−1, the sensor linearity of the responses in the range of 1–40 ppm is about 0.996. Response time, detection limit, reproducibility, and stability were characterized as well. When exposed to some known interference vapors, the sensors are much more sensitive to DMMP vapor. These results support that the SWNT flexible sensors are promising in portable on-site detection.