Detection and discrimination of low concentration explosives using MOS nanoparticle sensors

Abstract

In the present study, four explosives of NH 4NO 3, mineral explosives (ME), picric acid (PA) and 2,6-dinitrotoluene (2,6-DNT) have been investigated by using ZnO-doped nanoparticle sensors with additives of Sb 2O 3, TiO 2, V 2O 5 and WO 3. Firstly, eighteen ZnO-doped nanoparticle sensors were optimized and selected six best sensors to compose a new optimized array. Then, the detection capability of the sensor array was studied by using static sampling method. The results showed that with the increase in concentration of samples, the sensitivities of the sensors also increased, and the lowest detection limit of the four samples were low to 3.34 μg/L. At last, for the sake of approaching closer practical application, these four explosives were also studied with full dynamic sampling method and the results demonstrated that all the samples could be well identified completely at the concentration of 15.4 μg/L when maximum values of slope were extracted as the feature parameters to DFA analysis.