Detection of trace organics in Martian soil analogs using fluorescence-free surface enhanced 1064-nm Raman Spectroscopy.

A significant technology challenge in planetary missions is the in situ detection of organics at the sub-part-per-million (ppm) level in soils. This article reports the organic compound detection in Mars-like soils at the sub-ppm level using an ultra-sensitive spectral sensing technique based on fluorescence-free surface-enhanced Raman scattering (SERS), which has a significantly improved sensitivity and reduced fluorescence noise. Raman spectral detection of ppm level organics in Antarctic Dry Valley and Mojave Desert soils have been obtained for the first time, which otherwise are not detected by other Raman spectral techniques. (C) 2016 Optical Society of America