Functionalized Surfaces Based on Conducting Polymers and Carbon Nanotubes for Gas Sensing Applications

The high surface area, size, hollow geometry and chemical inertness remarkable properties of CNTs make them attractive for demanding applications in the field of gas sensing. To date studies on possible applications of CNTs have been focused either on individual single-walled carbon nanotubes (SWNTs) as sensitive materials towards O2, NO2 and NH3 [1-4] or on multi-walled carbon nanotubes (MWNTs) mats as NH3, CO, CO2 humidity and O2 gas sensors [5-7]. Nanotube sensors offer significant advantages over conventional metal-oxidebased electrical sensor materials in terms of sensitivity and small sizes needed for miniaturization and construction of massive sensor arrays. Nevertheless, several outstanding issues remain. Firstly, for sensing purposes, it is desirable to reliably obtain devices consisting of semiconductor CNTs operating at room temperature [1,4,8,9]. Secondly, molecular sensing requires strong interactions between a sensor material and target molecules. This is also the case for nanotubes.