DNA-based nanoelectronics

We discuss the basic inspiration underlying the drive towards using DNA molecules for nanotechnological applications, and focus on their potential use to develop novel nanoelectronic devices. We thus review the current level of understanding of the behavior of DNA polymers as conducting wires, based on experimental and theoretical investigations of the electronic properties, determined by the π-π superposition along the helical stack. First, the importance of immobilizing molecules onto inorganic substrates in view of technological applications is outlined: selected observations by suitable imaging techniques are noted. Then, the emphasis is shifted to investigations of the electronic structure: disappointing evidence for negligible conductivity, from both theory and experiment, on double-stranded DNA molecules, has recently been counterbalanced by clear-cut measurements of high currents under controlled experimental conditions that rely on avoiding nonspecific molecule-substrate interactions and realizing electrode-molecule covalent binding. As a parallel effort, scientists are now tracing the route toward the exploration of tailored DNA derivatives that may exhibit enhanced conductivity. We illustrate a few promising candidates and the first studies on such novel molecular wires.