Functionalized Carbon Nanotube-Based Sensors for Detecting a Trace Quantity of 2,4-Dinitrotoluene Explosive Vapors, with Selectivity

摘要

Stable, surfactant-free semiconducting carbon nanotube (CNT) inks were developed. The inks were functionalized with π-bonder receptor molecules to achieve selectivity toward DNT and TNT molecules. Two types of CNT sensors, interdigitated electrode (IDE) and thin-film transistor (TFT) sensors were printed and were tested with DNT vapor and other analytes. The CNT IDE sensors were able to repeatedly detect DNT vapor levels as low as 0.5 ppb with a response time of less than 10 seconds. These sensors showed a high degree of selectivity toward DNT over nitrobenzene and nicotine. Sensor sensitivity was found to increase with an increase in receptor molecules present in the CNTs. Preliminary results on a CNT TFT sensor showed a response to 300 ppb of DNT, a response similar to that of an IDE sensor prepared with CNTs with the same level of functionalization. Preparation and testing of sensors (especially TFT sensors) made with more functionalized CNT inks are ongoing.