Water quality monitoring is crucial for long-duration space missions, especially aboard spacecraft like the International Space Station (ISS). Traditional methods involve sending water samples back to Earth for analysis, which can identify new contaminants but still lacks the immediacy needed for ensuring astronauts' safety in real-time. To bridge this gap, the Spacecraft Water Analysis with Nanopore (SWAN) system has been developed. This innovative system uses solid-state nanopore technology combined with selective aptamers (artificial antibodies) for on-site water testing. SWAN operates by detecting molecule-specific pore occlusions in the nanopore system, identifiable by changes in electrical current. Each aptamer-analyte complex generates a unique electrical signature, allowing for precise detection of contaminants. The system has shown high sensitivity in detecting mercury and lead ions on Earth. SWAN's miniaturization and adaptability make it an ideal candidate for in-space water analysis, complementing existing tools and enhancing NASA's capabilities for future missions. However, one challenge with SWAN is the need for specific aptamers for new contaminants. Generating these aptamers on the ISS is impractical due to limitations in equipment, expertise, and resources. To overcome this, our perspective involves identifying new contaminants either on the ISS or Earth, followed by aptamer screening and selection on Earth. Once an aptamer for a new contaminant, like dimethylsilanediol (DMSD), is developed on Earth, its sequence is transmitted to the ISS. Astronauts then use a portable DNA synthesizer to create the aptamer in space, allowing for routine monitoring of the new contaminant using the SWAN system. This approach could potentially ensure the safety and sustainability of water resources in space exploration by enabling timely, efficient detection of low-concentration contaminants and adapting to various targets. The integration of SWAN with a portable DNA synthesizer and remote aptamer generation paves the way for a more self-sufficient and responsive water analysis system in space.
Zolfigol et al. (Sun,) studied this question.