Self-Assembly of DNA-Templated Polypyrrole Nanowires: Spontaneous Formation of Conductive Nanoropes

Polypyrrole nanowires formed by polymerization of pyrrole on a DNA template self‐assemble into rope‐like structures. These ‘nanoropes’ may be quite smooth (diameters 5–30 nm) or may show frayed ends where individual strands are visible. A combination of electric force microscopy, conductive atomic force microscopy and two‐terminal current–voltage measurements show that they are conductive. Nanoropes adhere more weakly to hydrophobic surfaces prepared by silanization of SiO2 than to the clean oxide; this effect can be used to aid the combing of the nanoropes across microelectrode devices for electrical characterization. DNA‐templated polypyrrole nanowires spontaneously assemble to form conductive nanoropes. These structures are visible in atomic force microscopy and their conductivity can be observed by cAFM and electric force microscopy. The figure shows an example of a nanorope where the individual strands of the rope are visible at one end because the rope has partially unravelled.