Laser Ablation Surface-Enhanced Raman Microspectroscopy

Improved identification of trace organic compounds in complex matrixes is critical for a variety of fields such as material science, heritage science, and forensics. Surface-enhanced Raman scattering (SERS) is a vibrational spectroscopy technique that can attain single-molecule sensitivity and has been shown to complement mass spectrometry, but lacks widespread application without a robust method that utilizes the effect. We demonstrate a new, highly sensitive, and widely applicable approach to SERS analysis based on laser ablation in the presence of a tailored,plasmonic substrate. We analyze several challenging compounds, including non-water-soluble pigments and dyed leather from an ancient Egyptian Chariot, achieving sensitivity as high as 120 amol for a 1:1 signal-to-noise ratio and 5 mu m spatial resolution. This represents orders of magnitude improvement in spatial resolution and sensitivity compared to those of other SERS approaches intended for widespread application, greatly increasing the applicability of SERS.