Description: The approach is to verify the effectiveness of two stringent organic decontamination strategies: electron beam irradiation and heat treatment. These protocols will be applied to a prototype nonaqueous microfluidic system for lipid biomarker detection. The work will quantify contaminant fatty acids and amino acids present on components used in nonaqueous microfluidic devices (e.g., glass manifolds, valves and membranes), and determine which stringent cleaning method (either electron beam irradiation or heat treatment) is more effective at destroying fatty acid and amino acid contaminants.

Benefits: NASA's life detection missions will focus on detection of biomarkers, including lipids. The limits of detection (LOD) for biomarkers are low, typically in the parts per trillion range. Stringent decontamination (removal of biomarkers) is critical to prevent a false positive in the search for life. Current decontamination methods for spacecraft instrumentation have focused on sterilization to remove viable organisms. However, life detection instruments will require a step further than sterilization: destruction of organic contaminants. Therefore, we aim to develop and verify contaminant mitigation strategies for the next generation of life detection instruments that can provide unprecedented levels of cleanliness. We studied the efficacy of Electron Beam Irradiation (EBI) as a potential technique for destroying molecular lipid contaminants from life detection instrument hardware. EBI has been successfully implemented for sterilization in the food, medical, and wastewater treatment industries for its ability to effectively kill bacteria and destroy DNA molecules without seriously degrading underlying materials, and has been proposed for spaceflight and Planetary Protection applications. We found that EBI was unable to quantifiably break down any of our target lipid molecules and should not be used for removing biomolecular contaminants. However, resistance to breakdown suggests that lipids may have significant lifetimes in environments with a high electron flux and thus considered a biomarker of interest for further study and life detection surveys.