Surface Enhanced Raman Scattering (SERS) Detection of Ammonium Nitrate (AN) Samples Fabricated Using Drop-on-Demand Inkjet Technology on Commercial and Fabricated SERS Substrates.

摘要

The U.S. Army and first responder community are increasingly focusing efforts on energetic materials detection and identification. Main hazards encountered in theater include homemade explosives (HMEs) and improvised explosive devices (IEDs), in part fabricated from simple components like ammonium nitrate (AN). In order to accurately detect and identify these unknowns (energetic or benign), fielded detection systems must be accurately trained using well-understood universal testing substrates. These training substrates must contain target species at known concentrations and recognized polymorphic phases. AN is an explosive precursor material that demonstrates several different polymorphic phases depending on how the material is deposited onto testing substrates. In this report, known concentrations of AN were uniformly deposited onto commercially available surface enhanced Raman scattering (SERS) substrates using a drop-on-demand inkjet printing system. The phase changes observed after the deposition of AN under several solvent conditions are investigated. Characteristics of the collected SERS spectra of AN are discussed and it is demonstrated that an understanding of the exact nature of the AN samples deposited results in an increased ability to accurately and reliably train hazard detection systems.