Differential Charging in Photoemission from Mercurated DNA Monolayers on Ferromagnetic Films.
Nano Lett
; 20(2): 1218-1225, 2020 02 12.
Article
em En
| MEDLINE
| ID: mdl-31960675
ABSTRACT
Spin-dependent and enantioselective electron-molecule scattering occurs in photoelectron transmission through chiral molecular films. This spin selectivity leads to electron spin filtering by molecular helices, with increasing magnitude concomitant with increasing numbers of helical turns. Using ultraviolet photoelectron spectroscopy, we measured spin-selective surface charging accompanying photoemission from ferromagnetic substrates functionalized with monolayers of mercurated DNA hairpins that constitute only one helical turn. Mercury ions bind specifically at thymine-thymine mismatches within self-hybridized single-stranded DNA, enabling precise control over the number and position of Hg2+ along the helical axis. Differential charging of the organic layers, manifested as substrate-magnetization-dependent photoionization energies, was observed for DNA hairpins containing Hg2+; no differences were measured for hairpin monolayers in the absence of Hg2+. Inversion of the DNA helical secondary structure at increased metal loading led to complementary inversion in spin selectivity. We attribute these results to increased scattering probabilities from relativistic enhancement of spin-orbit interactions in mercurated DNA.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
DNA
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DNA de Cadeia Simples
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Imãs
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Mercúrio
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article