A novel miniature confocal microscope/Raman spectrometer system for biomolecular analysis on future Mars missions after Antarctic trials

Biomolecules, such as the productive and protective pigments of photosynthetic organisms, are good biomarkers in extreme Antarctic deserts as analogues of early Mars. Laser Raman technology at long wavelengths which minimize fluorescence is ideal for remote analysis of biomolecules in situ. We report Raman spectra obtained with a prototype miniature laser-Raman spectrometer/confocal microscope (specification < 1 kg) under development for a Mars lander and evaluation in Antarctic deserts. We compare the efficiency of its 852 nm laser/CCD detector system with an optimal bench-top 1064 nm FT Raman spectrometer which excels with biomolecules. Using a yellow Antarctic lichen, Acarospora chlorophana, we show good correlation between both instruments restricted to the 460–1350 cm−1 wavenumber range.