Mars Organic Detector III: A Versatile Instrument for Detection of Bio-organic Signatures on Mars

Recent advances in the development of microfabricated lab-on-a-chip analysis systems have enhanced the feasibility and capabilities of in situ chemical and biochemical analyzers. While a wide variety of bio-organic molecules can be probed, we have focused our initial studies on the development of an amino acid analyzer with the hypothesis that extraterrestrial life would be based on homochiral amino acid polymers. In previous work, we developed a prototype electrophoresis chip, detection system and analysis method where the hydrolyzed amino acids were labeled with fluorescein and then analyzed in minutes via a capillary zone electrophoresis (CZE) separation in the presence of γcyclodextrin as the chiral recognition agent. In more recent work, we have demonstrated the feasibility of performing amino acid composition and chirality analyses using fluorescamine as the labeling reagent. Fluorescamine is advantageous because it reacts more rapidly with amino acids, has a low fluorescence background and because such a chemistry would interface directly with the Mars Organic Detector (MOD-I) concept being developed at Scripps. A more advanced analysis system called MOD-III is introduced here with the ability to analyze zwitterionic amino acids, nucleobases, sugars, and organic acids and bases using novel capture matrix chemistries. MOD-III, which is enabled by the nanoliter valves, pumps and reactors presented here, will provide a wide spectrum of organic chemical analyses and is suitable for a variety of in situ missions.