Micro-Detection System for Determination of the Biotic or Abiotic Origin of Amino Acids
The research carried out under this PIDDP involves the development of a breadboard version of a spacecraft-based system for the detection of amino acid chirality (molecular handedness) on solar system bodies. Chirality provides an unambiguous way of distinguishing between abiotic and biotic origins since only one mirror-image form is used in the functional molecules of life. Recent advances in a variety of nano-fabrication technologies have resulted in concepts for enabling miniaturized chemical and biological analytical systems. These are complete application-specific systems that integrate fluid micro handling systems for extracting and reacting target molecules, micro-separation technologies for enhanced sensitivity and resolution, and advanced detection technologies. This effort makes use of a relatively new technology that shows demonstrated promise for spacecraft-based amino acid analysis: microchip-based capillary electrophoresis (μCE). The μCE system is capable of analyzing the type of amino acids present as well as the relative amounts of their mirror image forms. The system we developed will be able to chirally resolve all of the major amino acids found in extraterrestrial material (Gly, Ala, Val, Pro, Asp, Glu, a-aminoisobutyric acid, and isovaline) at sub-part-per-billion levels. The -CE analysis requires that the amino acids be extracted from the sample and derivatized for either optical or electrochemical detection. In our implementation, the amino acids are released from the sample by sublimation and prepared for μCE analysis using a microfluidic circuit. In addition, we have investigated the use of a microfluidic circuit for the release of amino acids from samples in which sublimation has proven to be problematic.