Semi Empirical Evaluation of Shortest Amino acid (i.e., Glycine) as molecular device

Gaurav SikriEmail

Ravinder Singh SawhneyEmail

Ravinder KumarEmail

Department of Electronics Technology, Guru Nanak Dev University, Amritsar, India, 143005

Abstract

Glycine as the smallest biomolecule among amino acids, is bridged between symmetrical Au (111), Ag (111), Cu (111), Pt (111) and Pd (111) electrodes. The molecule-electrode coupling and switching characteristics are calculated using semi-empirical Extended Hückel Theory. This study manifests that the glycine molecule offers the strongest coupling with Au (111), Cu (111) and Pt (111) while the weakest coupling with Ag (111) and Pd (111) electrodes. Such molecule-electrode coupling is depicted by using projected device density of states, zero bias transmission spectra and conductance curves. Glycine offers significant rectification ratio (RR) besides multiple negative differential resistance (NDR) regimes with all the five electrodes. It offers the highest RR of 13.20 and significant NDR regime with the peak to valley current ratio of 6.74 with palladium electrodes. The switching characteristics are elucidated by transmission spectra and transmission pathway. Glycine based molecular device can act as the smallest switch in protein-based electronics family i.e., Proteotronics

Semi Empirical Evaluation of Shortest Amino acid (i.e., Glycine) as molecular device