Detection of Explosives by SERS Platform Using Metal Nanogap Substrates

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Ensuring personal safety necessitates the detection of trace explosive amounts.
• Laser-based spectroscopy techniques offer a viable method for explosive detection.

Purpose of the Study:

• To develop and demonstrate a sensitive method for detecting nitro-based explosives in solution.
• To utilize surface-enhanced Raman scattering (SERS) with plasmonic nanogap substrates for enhanced detection.

Main Methods:

• Surface-enhanced Raman scattering (SERS) was performed using plasmonic nanogap substrates.
• Nitro-based compounds (TNT, RDX, PETN) were analyzed in solution using acetone or water/hexane as solvents.
• A low excitation wavelength (785 nm) and low incident power (≈0.1 mW) were employed.

Main Results:

• SERS detection of TNT, RDX, and PETN was achieved with high sensitivity, down to picomolar concentrations.
• Distinct SERS spectral variations were observed for different explosives, facilitating identification.
• The 'hot spot' effect at the nanogap significantly enhanced the Raman signal.

Conclusions:

• Plasmonic nanogap substrates provide an effective platform for sensitive explosives identification.
• The developed SERS approach offers a promising tool for trace explosive detection.
• The spectral fingerprinting capability aids in distinguishing various nitro-based compounds.