Ricerc@Sapienza

Amino-acids recognition and fast, cheap and reliable methods for proteins and peptides sequencing is a serious bottleneck for the rising of proteomics, i.e. the study of the proteins content and their functionality within a cell. The current experimental techniques preclude the reliable sequencing of the huge protein population within a single cell that is two orders of magnitude larger than the human genome.
Recently many applications of nano-devices and nano-structured materials have allowed the development of new nano-technology strategies to attain DNA sequencing using, for instance, the ion blockade current signals flowing through a nanopore during DNA translocation. However such strategy is of little aid in the case of protein sequencing for many reasons related, basically, to the more complex variety of objects to be detected.
As an alternative approach, transverse current measurements through nano-gaps have been considered for protein sequencing using mainly Au based nano-device.
The present project is oriented to study new graphene based nano-devices for amino-acids recognition and protein sequencing through quantum tunneling current measurements during the protein or peptide translocation across a nano-gap in graphene nano-ribbons. Previous results have shown the atomistic an atomistic scale resolution allowing the detection of single peptide bonds and the amino-acid recognition.
The nano-structured physical system and phenomena of interest involve several aspects and are approached in the context of ab-initio calculations based on the density functional theory and the non equilibrium Green function method. Small peptides with a-polar, polar and charged amino-acids are addressed and both elastic and inelastic scattering phenomena are considered due to local vibrational modes and phonon assisted tunneling events.