Dresden 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
DS: Fachverband Dünne Schichten
DS 20: Poster
DS 20.47: Poster
Thursday, March 12, 2026, 18:30–20:30, P2
Modeling intermolecular interactions and ordered packing in self-assembled monolayers of polyalanine α-helices — Hadis Ghodrati Saeini1, Thi Ngoc Ha Nguyen1, Christoph Tegenkamp1, Sibylle Gemming1, Jeffrey Kelling2, and •Florian Günther3 — 1Technische Universität Chemnitz, Chemnitz, Germany — 2Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — 3São Paulo State University, Rio Claro, Brazil
Polypeptide molecules are attracting attention as promising candidates for electronic spin-filters due to the phenomenon of chiral-induced spin selectivity (CISS). This motivates substantial research to characterize the structural and electrical properties of self-assembled monolayers (SAMs) of peptide helices, for example, polyalanine (PA) α-helices. In this work, we aim to characterize the intermolecular interactions governing PA-SAM film formation. We developed an empirical potential that models the interaction between two isolated helices, derived using the density functional-based tight-binding (DFTB) method. This potential allowed us to simulate the most energetically favorable arrangements in SAM films via a Monte Carlo approach employing simulated annealing and the Metropolis algorithm. Statistical analysis of the relative positioning of adjacent molecules enabled us to classify the degree of frustration in the films. For enantiopure systems, a frustration-free arrangement was found, yielding a perfect hexagonal lattice. For mixtures of chiralities, the results showed parallel-aligned domains of differently handed helices. Both findings are in excellent agreement with experimental works.
Keywords: self-assembly; polyalanine alpha-helices; Monte Carlo simulation