| Mars has long been of interest to the scientific community and recent results from the Rovers Spirit and Opportunity as well as Phoenix have shown that water once flowed on the planet surface; however, while the presence of water suggests life, the discovery of biomarkers has yet to be achieved. For my thesis, I designed, engineered and tested the Multichannel Mars Organic Analyzer (McMOA), a compact, robust and sensitive autonomous instrument for in situ detection and analysis of chemical biomarkers by microchip capillary electrophoresis (CE). The McMOA uniquely provides a device for autonomous multichannel analysis with real-time fluorescence spectral detection.;I first demonstrated the analysis of organic compounds, including amino acid biomarkers and polycyclic aromatic hydrocarbons (PAHs), using a four-layer microchip that contains eight CE analysis channels integrated with an autonomous fluidic routing network. I showed the automated sequential analysis of a sample in each channel and eight consecutive analyses of alternating samples on the same channel demonstrating less than 1% cross contamination. The instrumental limit of detection is 6 pM. The McMOA was used to identify the fluorescence spectra of nine PAHs and applied to the analysis of a sediment sample from Lake Erie. The presence of benzo[a]pyrene and perylene in this sample was confirmed and a peak coeluting with anthanthrene was disqualified, based on spectral analysis.;In subsequent work, I developed the microfluidic processor that achieves serial dilution, derivatization, sample routing, and analysis. The novel pneumatic microvalve-based mixing structure was shown to be effective at mixing fluids while conserving on-chip real-estate. The microfluidic architecture avoids reagent cross-contamination and rapidly generates sufficient volumes of mixed reagents for analysis. Integrated with a capillary electrophoresis (CE) channel, this structure successfully demonstrated precise metering and automated serial dilution of an amino acid standard followed by analysis. On-chip derivatization and analysis of a sake sample accurately quantified a panel of aldehydes and ketones, confirming the performance of this structure for autonomous sample preparation, dilution, and analysis.;The McMOA exploits lab-on-a-chip technologies to fully integrate complex autonomous operations demonstrating the facile engineering of microchip-CE platforms---a major step towards a space-ready instrument for planetary exploration. |
