Peptide bond recognition via vibration assisted electron tunneling in graphene nano device

Inelastic scattering due to vibrations is considered in the transver- sal tunneling current recognition of amino acids across a nano gap in graphene nanoribbons. Phonons and local vibrational modes assisted current tunneling is calculated by treating the electron-phonon scattering in the context of the lowest order expansion of the self-consistent Born approximation. We study the Gly and Ala homo-peptide cases as an example of very similar, small and neutral amino- acid that would be undistinguishable by means of standard techniques, such as the ionic blockade current, in real peptides. We show that all the inelastic contribu- tions to the tunneling current are in the bias range 0 V ≤ V ≤ 0.5 V and that they can be classified, from the atomistic point of view, in terms of energy sub-ranges they belong to. Peculiar fingerprints can be found for the typical configurations that have been recently found for peptide bonds recognition by tunneling current.