Development and evaluation of a microdevice for amino acid biomarker detection and analysis on Mars

TLDR

The MOA microdevice is a four‑wafer sandwich comprising glass CE separation channels, microfabricated pneumatic valves and pumps, and a nanoliter fluidic network, integrated with high‑voltage CE power supplies, pneumatic controls, and fluorescence detection optics for portable field operation. The MOA achieved micromolar to 0.1 nM (part‑per‑trillion) sensitivity, detecting 10–600 ppb amino acids in Atacama soil extracts and 70 ppt–100 ppb in Panoche Valley jarosite, demonstrating its feasibility for in‑situ amino‑acid biomarker analysis on Mars‑like soils.

Abstract

The Mars Organic Analyzer (MOA), a microfabricated capillary electrophoresis (CE) instrument for sensitive amino acid biomarker analysis, has been developed and evaluated. The microdevice consists of a four-wafer sandwich combining glass CE separation channels, microfabricated pneumatic membrane valves and pumps, and a nanoliter fluidic network. The portable MOA instrument integrates high voltage CE power supplies, pneumatic controls, and fluorescence detection optics necessary for field operation. The amino acid concentration sensitivities range from micromolar to 0.1 nM, corresponding to part-per-trillion sensitivity. The MOA was first used in the lab to analyze soil extracts from the Atacama Desert, Chile, detecting amino acids ranging from 10–600 parts per billion. Field tests of the MOA in the Panoche Valley, CA, successfully detected amino acids at 70 parts per trillion to 100 parts per billion in jarosite, a sulfate-rich mineral associated with liquid water that was recently detected on Mars. These results demonstrate the feasibility of using the MOA to perform sensitive in situ amino acid biomarker analysis on soil samples representative of a Mars-like environment.