| AVS 54th International Symposium | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS-TuP |
| Session: | Nanometer-scale Science and Technology Poster Session I |
| Presenter: | A.R. Krause, University of Tennessee, Oak Ridge National Laboratory |
| Authors: | A.R. Krause, University of Tennessee, Oak Ridge National Laboratory D. Yi, Oak Ridge National Laboratory T.G. Thundat, Oak Ridge National Laboratory |
| Correspondent: | Click to Email |
Microcantilever arrays offer a miniature, cost effective, and real-time sensor platform for trace explosive detection for combating the terrorist threat. Selectivity in detection in microcantilever arrays is achieved by using receptor layers immobilized on the cantilever surfaces. Despite their high sensitivity and the ability for array-based detection of multiple analytes in real-time, cantilever-based sensor platforms exhibit poor selectivity due to the lack of highly selective receptor layers. Selectivity based on array-based detection and pattern recognition often fails due to the lack of orthogonality in sensor array responses due to the limited number of interactions forming a basis for receptor-analyte interactions. We have developed a receptor-free detection method that can provide high selectivity in explosive vapor detection. In this method adsorbed explosives molecules are allowed to undergo chemical reactions with locally generated ozone to provide an analyte specific cantilever response. The explosive molecules from a vapor generator calibrated with GC-mass spectrometer were first allowed to condense on the cantilever surface. The adsorbed molecules were then exposed to ozone created by a miniature UV lamp for a short period of time and the cantilever responses were recorded as a function of exposure time. We have used a piezoresistive cantilever array in common mode rejection to achieve high selectivity and sensitivity. Recent results for selective and sensitive detection of TNT, RDX, and PETN using this method will be presented.