Functionalized metallic carbon nanotube arrays for gas phase explosives detection

[Display omitted] •Experiments on explosive sensing are problematic, complicated by safety concerns.•Functionalized carbon nanotubes offer important opportunities in explosives detection research.•Nonlinear chemiresistive response expands the sensor data base available for selective detection. Gas phase detection of explosive molecules is a sensing application of wide interest. Light weight, low power sensors are needed for mobility and wide dissemination, however low vapor pressures and the presence of similar functional groups in a variety of explosive molecules make the development of sensitive and selective detection systems difficult. Experimental research has reported some success in the development of carbon nanotube (CNT) based explosives sensors, however safety considerations and strict controls on the distribution of explosive materials hamper experimental progress. Ab initio modeling of functionalized carbon nanotubes suggests that chemiresistive sensor arrays employing hydroxyl, carboxylic acid, oxygen, and amine groups can distinguish common background gases from both nitroaromatic and nitramine explosives, distinguish between nitroaromatic and nitramine explosives, and distinuguish similar nitramine explosives from each other. The modeling results on functionalized CNT sensing arrays suggest that they offer important opportunities for future experimental research.