Preparation and Characterization of Conductive and Photoluminescent DNA-Templated Polyindole Nanowires

Abstract

Polyindole (PIn) nanowires were formed on a lambda-DNA template by chemical oxidation of indole using aqueous FeCl3. The resulting nanowires are smooth, regular, conductive and had diameters in the range of 5-30 nm. These features allow them to be aligned by molecular combing and studied by scanned conductance microscopy, conductive AFM, and two-terminal I-V measurements. Using this combination of measurements, we find that the conductivity of PIn/DNA nanowires is between 2.5 and 40 S cm(-1) at room temperature, which is substantially greater than that in previous reports on the bulk polyindole conductivity (typically 10(-2)-10(-1) S cm(-1)). The conductance at zero bias shows an Arrhenius-type of dependence on temperature over the range of 233 to 373 K, and the values observed upon heating and cooling are repeatable within 5%; this behavior is consistent with a hopping mechanism of conductivity.

A Nonconventional Approach to Patterned Nanoarrays of DNA Strands for Template‐Assisted Assembly of Polyfluorene Nanowires

“…DNA self‐assembly has attracted significant attention as it offers a bottom‐up manufacturing technique to provide efficient templates for the subsequent assembly of either organic or inorganic nanoelements such as metallic charged nanoparticles or streptavidin proteins . Surface modification of individual DNAs and their configurations is of crucial importance to develop nanoscale devices based on DNA‐templated assembly . In this context, the specific immobilization of a large number of DNA molecules on a solid substrate has progressed over the past years for many potential applications such as electronic, magnetic, optoelectronic, and sensors, in which DNA molecules are “addressable” only when they are highly ordered or stretched.…”

A novel, rapid synthetic protocol for controllable sizes, conductivities and monomer units of soluble polypyrrole

“…This leads to impressive alterations in optical as well as physico-chemical properties. Several conducting polymers viz polypyrrole (PPy), polyaniline, polythiophene, polyindole, polyethylenedioxy thiophene have been widely employed during the past few decades [9][10][11][12][13][14]. Among these conducting polymers, PPy has attracted great interest due to its ease of preparation, wide conductivity range (10 À2 to 10 4 S cm À1 ), satisfactory environmental stability and biocompatibility.…”

Fabrication of Conducting Polymer Nanowires

“…Moon et al (2010) also chemically polymerized polypyrrole nanowires using DNA as a template on a (3-aminopropyl)triethoxysilane modified silicon wafer with ammonium persulfate as an oxidant. Hassanien et al (2010) reported that polyindole nanowires were synthesized on a -DNA template by chemical oxidation of indole using FeCl 3 as an oxidant. Figure 3 shows AFM images of conducting polymer nanowires using DNA as a template.…”

“…Figure 3 shows AFM images of conducting polymer nanowires using DNA as a template. (Dong et al, 2007); (b) DNA/polypyrrole nanowire (Moon et al, 2010); (c) DNA/polyindole nanowires aligned between Au electrodes (Hassanien et al, 2010).…”