Nanostructured TiO2 thin films are found to be highly responsive to trace vapors of common nitro-explosives at room
temperature. Thin films of TiO2 nanowires, made with high yield hydrothermal synthesis, present very reliable sensing
characteristics to nitro-aromatic molecules with high sensitivity and fast response at ambient condition. The detection
limit of 2, 4-dinitrotoluene (DNT) vapor at room temperature could reach up to 3ppb. The experimental results indicate
titania nanowires as a novel chemical sensor to explosive gas have a great commercial potential due to its unique
advantages: high sensitivity, rapid response and recovery, small size suitable for intergration with microelectronics and
low fabrication cost. Experimental results and a theoretical model are presented.