Nanowire Gas Sensors

This research work is concerned with the synthesis, chemical and structural characterisation of conductive polymers (CPs) DNA templated nanowires and construction of gas sensors for volatile organic compounds (VOCs) and ammonia. The sensing elements are based on conductive polymers (Imidazole, Im; Indole, In; and pyrrole, Py) nanowires created using a simple and low cost fabrication method that applied DNA as a template on which to carry out the polymerisation. The CPs/DNA nanowires are synthesised in solution and aligned on an oxidised silicon substrate by the molecular combing method that relies on a combination of fluid flow and surface tension forces.The chemical properties of the nanowires were probed using different spectroscopic techniques such as X-ray Photoelectron Spectroscopy (XPS), Ultra-Violet Visible (UV-Vis) spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy and Atomic force (AFM) and electron microscopy (SEM and TEM) were used to characterise the nanowire dimensions. These techniques together demonstrated the formation of a supramolecular hybrid polymer containing DNA and conductive polymers.