AVS 49th International Symposium
    Homeland Security Wednesday Sessions
       Session HS+SS+BI-WeA

Paper HS+SS+BI-WeA8
Real-time Detection of TNT Using Microcantilevers with Microcyclic Cavitand Coatings@footnote 1@

Wednesday, November 6, 2002, 4:20 pm, Room C-209

Session: Chemical and Biological Detection
Presenter: N.V. Lavrik, Oak Ridge National Laboratory
Authors: N.V. Lavrik, Oak Ridge National Laboratory
T. Thundat, Oak Ridge National Laboratory
G. Muralidharan, Oak Ridge National Laboratory
P.G. Datskos, Oak Ridge National Laboratory
Correspondent: Click to Email
Real-time detection of nitroaromatic aromatic explosive compounds in various environments is a highly significant task in forensics, anti-terrorist activities and global de-mining projects. In particular, ability to detect trace levels of trinitrotoluene (TNT) in air and soil could greatly reduce continued fatalities from land mines among civilians and be a measure in tracking and locating explosive materials. In our work, we address this challenge of detecting TNT vapors in gaseous environment by using an innovative, highly sensitive microcantilever transducer combined with a chemically sensitive molecular coating based on the macrocyclic cavitand of a calixarene family. We measured responses to vapors of TNT and its analogs, 0-mononitrotoluene and 2,4-dinitrotoluene vapors in the range of temperatures of 298 K to 318 K. Our results were used in order to estimate the limits of detection (LODs) for these compounds and optimize the temperature regime of the designed detection system. In the case of TNT, the steady state responses were large, however, the response kinetics was significantly elongated, which is consistent with an analyte depletion model. As compared to more traditional surface acoustic wave sensors with a proven potential for detection of TNT, our approaches offer a simpler, low-cost alternative without sacrificing the performance. The reported results together with these advantages of microcantilever based gas detectors clearly indicate a viable technological approach to mass produced detectors of explosive materials. @FootnoteText@ @footnote 1@ This work was supported by the U.S. Department of Energy and Micro Sensor Technologies, Inc. Oak Ridge National Laboratory is operated for the U.S. Department of Energy by UT-Battelle under contract DE-AC05-96OR22464.