Life on Mars, if it exists, could have been transferred between Earth and Mars due to meteorite impacts. The Search for Extra-Terrestrial Genomes (SETG; setg.mit.edu) is under development to enable the search for nucleic acid (DNA, RNA) based life on Earth and for diverse other space-related applications (e.g., Carr et al. 2017). In our prior ZeroG experiment (November 2017) we demonstrated a robust sequencing capability during parabolic flight using a small commercial device (Oxford Nanopore MinION Mk-1B) weighing ~ 100 g and powered by a USB port. This device detects double stranded DNA or single stranded RNA after appropriate library preparation, which consists of many enzymatic steps to prepare the nucleic acids (DNA, RNA) for sequencing. Life beyond Earth may or may not use standard nucleic acids, thus, the astrobiology community seeks devices capable of detecting not only DNA or RNA, but nucleic acids or other informational polymers. In addition, targeting other biomolecules that are stable over geologic time, such as amino acids, is highly desirable.
Here we propose to test an element of the Electronic Life-detection Instrument (ELI), specifically a solid-state single molecule detector. We propose to target amino acids and IPs, including nucleic acids, though note that, in principal, many other types of molecules could be detected. This versatility will support unambiguous life detection and detection of forward contamination. ELI relies on solid-state quantum electronic tunneling (QET) nanogap sensors (Fig. 1), which can detect and discriminate among single amino acids, and detect RNA and DNA, including bases and (in a very limited fashion) sequences.
The research goals of the experiment are to 1) Quantify the impact of g-level on the nanogap device, and 2) Quantify changes in noise due to g-level and vibration. In addition, we aim to perform single molecule detection of amino acids.
In the 2021 flight (originally planned for 2020), we are testing upgraded hardware that permits automatic real-time sub-nanometer gap control to improve the measurement fidelity of the system.
Instrument overview. A) ELIE will utilize an adjustable nanogap to measure at least two key biosignatures: 1) Amino acid abundance distribution, and 2) Presence of informational polymers, not limited to DNA and RNA. B) Nanogap chip. C)Single amino acid events (proline, 10 μM; 100 mV applied bias)
Team Members
Christopher E. Carr, Principal Investigator
Maria T. Zuber, Co-Investigator
Gary Ruvkun, Co-Investigator
Jason Soderblom, Co-Investigator
Jack Szostak, Co-Investigator
Masateru Taniguchi, Co-Investigator
Daniel Duzdevich, Postdoctoral Associate
Delson Faria Dasilva, Undergraduate Researcher
Spencer Meek, Summer High School Intern
Acknowledgements
MIT Media Lab Space Exploration Initiative (Zero-G Flight)
Funding: NASA 80NSSC19K1028
References
Carr CE, Mojarro A, Hachey J, Saboda K, Tani J, Bhattaru SA, Smith A, Pontefract A, Zuber MT, Finney M, Doebler R, Brown M, Talbot R, Nguyen V, Bailey R, Ferguson T, Church G, Ruvkun G. Towards In Situ Sequencing for Life Detection. Aerospace Conference, 2017 IEEE. March 4-11, Big Sky, MT, USA, pp. 1-18. Session 2.07 In Situ Instruments for Landed Surface Exploration, Orbiters and Flybys. Paper # 2353 doi:10.1109/AERO.2017.7943896
Di Ventra, M. & Taniguchi, M. in Nat Nano Vol. 11 117-126 (Nature Publishing Group, 2016).