Qualitative Monitoring of Proto-Peptide Condensation by Differential FTIR Spectroscopy.

Condensation processes such as wet-dry cycling are thought to have played significant roles in the emergence of proto-peptides. Here, we describe a simple and low-cost method, differential Fourier transform infrared (FTIR) spectroscopy, for qualitative analysis of peptide condensation products in model primordial reactions. We optimize differential FTIR for depsipeptides and apply this method to investigate their polymerization in the presence of extraterrestrial dust simulants.