Modeling and Testing of Molecular Wire Sensors To Detect a Nucleic Acid Base

Abstract

We report a theoretical study of molecular wires which are designed to detect a single nucleic acid base thymine, through electrical conductance change. Three model sensors with ethynylphenyl backbones having suitable detection units and capable of forming hydrogen bonds with thymine are proposed. A combination of density functional theory and nonequilibrium Green's function formalism were used for the theoretical studies. The results show that subtle changes in electronic properties of the sensors due to hydrogen bond formation with the target may give rise to measurable changes in conductance. We also report experimental conductance studies for one model sensor, which agrees qualitatively with the theoretical results.