keV ion irradiation assisted prebiotic synthesis of oligopeptide in the solar system Original Research Article

In this paper, keV ion assisted peptide formation from amino acid monomers is studied. To investigate the possible role of low energy ion irradiation in prebiotic synthesis of oligopeptides, we applied keV Ar+ and N+ ion beams to solid state phenylalanine. After ion irradiation, it was found that phenylalanine dipeptide was formed and the optimal pH value for peptide formation was 8–9. A radical mechanism was also deduced for our observations. In view of the ubiquitous existence of keV ions in early space and on the early Earth, we suggest that low energy charged particles might have played a role in chemical evolution in the solar system.