Nanoclay–Peptide Interfaces Mediate Prebiotic Chemical Evolution in the Origin of Life

The selective enrichment of biomolecules was crucial for the emergence of life; however, the mechanisms behind this process under prebiotic conditions remain incompletely understood. Natural nanoclays, which were abundant on early Earth, represent compelling candidates for concentrating organic molecules from dilute aqueous environments. This study investigates interfacial interactions between cation-exchanged montmorillonite nanoclays (Na⁺, Mg²⁺, and Fe³⁺) and representative oligopeptides, including basic (R10, K10) and acidic (E10, D10) peptides. Montmorillonite exhibited strong selectivity toward basic peptides, while Fe³⁺-MMT additionally promoted the degradation of acidic peptides via Fe(IV)═O. Molecular dynamics simulations provided detailed atomistic insights into the underlying mechanisms, highlighting the roles of charge complementarity and interlayer confinement in driving selective adsorption. These results demonstrate that nanoclay-peptide interfaces can both enrich functional oligomers and modulate their stability and reactivity, suggesting a nanoscale mechanism by which mineral surfaces regulated chemical evolution toward higher molecular complexity.