Characterization of Amino Acid Nanolayers and Their Interactions under Simulated Planetary Conditions

Laboratory experiments extend our possibility to understand the behavior of organic molecules under extraterrestrial conditions. In the scope of such simulation experiments, organic molecules are often prepared as thin films, embedded in ice matrices, or adsorbed onto mineral surfaces. Albeit a single-species approach often adequately mimics the conditions to be studied, there are scenarios where the interactions between different organic molecules should be considered. In this work, we investigate the interaction of the two simplest α-amino acids, glycine and alanine, while codeposited as homogeneous nanolayers. Our results demonstrate that their interaction leads to deposition patterns, infrared signatures, and electronic properties that cannot be predicted by studying each molecular species in isolation. We conclude that organic interactions influence the photochemistry and spectroscopic signatures of biomolecules potentially present in planetary environments of interest such as Titan’s surface.