Microfluidic Life Analyzer (MILA)

We will develop the Microfluidic Life Analyzer (MILA) to characterize organic compounds encountered on NASA missions at parts-per-billion levels. The MILA subsystem could be utilized on planetary in situ probes searching for habitable environments, prebiotic chemistry, and life, on alien worlds. MILA is a microchip-based ultrasensitive chemical analyzer that is capable of determining not only the chemical composition of key organics in samples, but also measuring distributions of key molecular properties that inform us of the processes involved in the formation of these materials. MILA focuses on measurements of amino acids (building blocks of terrestrial proteins) and carboxylic acids (associated with cellular membranes). We choose to analyze these targets not only because they are biomarkers for life as we know it on Earth, but an analysis of their molecular properties could also be used to help identify other truly alien forms of life. But regardless of the outcome in the search for life on planetary missions, there is still an overarching need for understanding of the nature of organic molecules present throughout our solar system. There are a myriad of forms organic molecules can take even in the absence of life. Understanding the nature of abiotic and potentially prebiotic chemistry on bodies such as Europa, Titan, or comets could inform us both of the origin of life on Earth as well as the potential for life elsewhere in the solar system. Hence MILA is relevant to all future in situ missions tasked with characterizing organics in the context of both abiotic and biological chemical pathways (e.g. from primitive bodies like comets with abiotic amino acids to potentially habitable environments like Mars, Europa, and Enceladus). In addition to detecting amino acids and carboxylic acids at parts-per-billion levels or lower, MILA would be capable of determining the identity and chirality of at least 20 different amino acids (simultaneously). MILA would also be capable of determining the distribution of carbon chain lengths of carboxylic acids present in these samples between 1 and 30 carbons. By measuring not only the compositions of these organic compounds, but their distributions, we gain valuable insight into the nature of the processes that acted during their formation. For example, life on Earth is based upon just one of the two possible chiral forms of amino acids, whereas abiotic meteoritic material contains approximately equal amounts of both forms. And biological carbon chains are generally built up two atoms at a time, in order to create a host of biological "Lego blocks" including phospholipid fatty acids (PLFAs), which have specific carbon chain lengths, and give cellular membranes their structure. MILA extends a legacy of NASA investment in highly successful R&A and SBIR programs. It utilizes the technique of microchip capillary electrophoresis for sample handling and separation, and laser-induced fluorescence (LIF) for ultrasensitive detection. Our team has considerably extended the state-of-the-art in this area both in microchip automation, chemical analysis, and end-to-end complete system function. Our liquid-based approach overcomes the published shortcomings of gas-phase analysis techniques, particularly when applied to samples containing minerals. To prove MILA's effectiveness in planetary missions, we will validate all our newly developed techniques on Mars-relevant, mineral-rich samples. We will also develop means for storing the fluorescent dyes necessary for our technique, and demonstrate that they are capable of surviving the multiple years required for interplanetary travel. This PICASSO effort will bring the TRL level of MILA from 3 to 5, and lead directly to a follow-on MatISSE-funded effort. MatISSE efforts would be directed towards merging MILA with liquid extraction subsystems to enable end-to-end analysis of powdered samples on planetary missions in the coming decade.