Nature Communications 2016-01-01

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

Meital Eckshtain-Levi, Eyal Capua, Sivan Refaely-Abramson, Soumyajit Sarkar, Yulian Gavrilov, Shinto P Mathew, Yossi Paltiel, Yaakov Levy, Leeor Kronik, Ron Naaman

Index: Nat. Commun. 7 , 10744, (2016)

Full Text: HTML

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.