Cold denaturation induces inversion of dipole and spin transfer in chiral peptide monolayers

Nat Commun. 2016 Feb 26:7:10744. doi: 10.1038/ncomms10744.

Abstract

Chirality-induced spin selectivity is a recently-discovered effect, which results in spin selectivity for electrons transmitted through chiral peptide monolayers. Here, we use this spin selectivity to probe the organization of self-assembled α-helix peptide monolayers and examine the relation between structural and spin transfer phenomena. We show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear one upon cooling. This process is similar to the known cold denaturation in peptides, but here the self-assembled monolayer plays the role of the solvent. The structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by a concomitant change in the spin that is preferred in electron transfer through the molecules, observed via a new solid-state hybrid organic-inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine
  • Aminoisobutyric Acids
  • Cold Temperature*
  • Electron Transport
  • Electrons
  • Molecular Dynamics Simulation
  • Oligopeptides / chemistry*
  • Protein Denaturation*
  • Protein Structure, Secondary*

Substances

  • Aminoisobutyric Acids
  • Oligopeptides
  • Alanine