Scanning Tunneling Microscopy and Spectroscopy of Novel Silver–Containing DNA Molecules

The quest for a suitable molecule to pave the way to molecular nanoelectronics has been met with obstacles for over a decade. Candidate molecules such as carbon nanotubes lack the appealing trait of self-assembly, while DNA seems to lack the desirable feature of conductivity. Silver-containing poly(dG)–poly(dC) DNA (E-DNA) molecules have recently been reported as promising candidates for molecular electronics, owing to the selectivity of their metallization, their thin and uniform structure, their resistance to deformation, and their maximum possible high conductivity. Ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) of E-DNA presents an elaborate high-resolution morphology characterization of these unique molecules, along with a detailed depiction of their electronic level structure. The energy levels found for E-DNA indicate a novel truly hybrid metal–molecule structure, potentially more conductive than other DNA-based alternatives.