Detection of Explosives by SERS Platform Using Metal Nanogap Substrates

Detecting trace amounts of explosives to ensure personal safety is important, and this is possible by using laser-based spectroscopy techniques. We performed surface-enhanced Raman scattering (SERS) using plasmonic nanogap substrates for the solution phase detection of some nitro-based compounds, taking advantage of the hot spot at the nanogap. An excitation wavelength of 785 nm with an incident power of as low as approximate to 0.1 mW was used to excite the nanogap substrates. Since both RDX and PETN cannot be dissolved in water, acetone was used as a solvent. TNT was dissolved in water as well as in hexane. The main SERS peaks of TNT, RDX, and PETN were clearly observed down to the order of picomolar concentration. The variations in SERS spectra observed from different explosives can be useful in distinguishing and identifying different nitro-based compounds. This result indicates that our nanogap substrates offer an effective approach for explosives identification.

Automated summary

Using surface-enhanced Raman scattering (SERS) techniques with plasmonic nanogap substrates, trace amounts of nitro-based compounds such as TNT, RDX, and PETN were effectively detected down to picomolar concentrations in solution. This method offers a powerful approach for identifying different explosives based on the variations in SERS spectra observed.