DNA-based conducting polymer nanowires for biosensor applications

Abstract

Novel DNA-based conductive polymer nanowires formed from thienyl-pyrrole derivatives have been synthesized and characterised by high-resolution ES-MS, ¹H and ¹³C NMR spectroscopy. Bulk DNA-templating of these materials is demonstrated by FTIR, while relative control over nanowire dimensions and deposition is shown by AFM. The electronic properties of these materials were investigated by Scanned Conductance Microscopy (SCM) and two-point I-V measurements. The resistance of the DNA/polymer nanowires, determined from variable temperature I-V measurements, was found to be in the range of 10¹²-10¹⁴Ω. Nanowire conductivity values were calculated to be in the range of 1.9x10-⁷-3.75x10-⁴S cm-¹ at 303K. FTIR data demonstrates the availability of the alkyne group in bulk DNAtemplated materials for subsequent nanowire functionalisation using ‘click’ chemistry. Efforts to couple 3-azido propanol and ssDNA probe DNA is also presented.