Gelation of functional peptides by trivalent cations at the air-water interface
Abstract
We report a mechanism for gelation at fluid interfaces driven by multivalent-cation-mediated bridging. At the air-water interface, peptides with bound lanthanide cations undergo a coordination-geometry transition that converts the metal from a single-peptide bound state to a multi-peptide bridging state, driving charge inversion and gel formation. Surface adsorption and non-ideal interfacial electrostatics are implicated in this transition. The gel is stabilized by reversible metal-ligand coordination bonds that resist bulk salt screening, fundamentally distinct from electrostatic charge-inversion gelation in proteins. This reveals the breakdown of the peptide's coordinating sphere as a distinct pathway for interfacial gelation, independent of the diffuse electrostatic mechanisms governing bulk protein aggregation.
Keywords
Cite
@article{arxiv.2607.14061,
title = {Gelation of functional peptides by trivalent cations at the air-water interface},
author = {Stephen A. Crane and Felipe Jimenez Angeles and Monica Olvera de la Cruz and Ivan J. Dmochowski and Kathleen J. Stebe},
journal= {arXiv preprint arXiv:2607.14061},
year = {2026}
}