Description
Carbon and nitrogen are two of the most important elements for biological molecules. On the early Earth (approx. 4 billion years ago), however, they were primarily found as very simple and stable compounds, such as nitrogen and carbon dioxide. How did essential organic molecules form from these relatively inert starting materials? High-energy natural phenomena, such as lightning strikes and radiolysis events, are likely to have been major drivers of these reactions. We have developed a plasma-electrochemical system to mimic these high-energy phenomena through high-voltage spark discharge. The negative electrode in the gas phase mimics a negative cloud layer, while the positive electrode immersed in the liquid and/or solid phase acts as the ground. This setup results in high-energy electrons bombarding starting materials in the reaction vessel, similar to a lightning strike or cosmic radiation activating inert chemicals found in the environment. The setup is highly tuneable, allowing us to simulate a wide variety of environments, such as the early Earth, other planets and even asteroids. Through techniques like optical emission spectroscopy and electron paramagnetic resonance, we are able to study the plasma generated in our system, as well as the reactions it drives. We have found that prebiotic synthesis likely proceeded through radical-driven reaction pathways that are very different from modern chemical synthesis. Understanding these mechanisms would help us uncover how the earliest organic molecules formed, both on Earth and in space. This platform provides a method of experimentally studying environments that cannot be probed directly, and could help inform our search for life elsewhere in the universe.
References:
Jiang, H. J.; Underwood, T. C.; Bell, J. G.; Whitesides, G. M. et al. Mimicking lightning-induced electrochemistry on the early Earth. Proceedings of the National Academy of Sciences 2024, 121 (32), e2400819121. DOI: 10.1073/pnas.2400819121.
| I am the presenting author | Yes |
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