Polyaniline (PAni) is an example of a conducting polymer whose properties (optical/electrical) change in response to the immediate environment of the material. PAni thus has huge potential for both sensing and electrostatic discharge applications. By focusing on PAni nanofibres we can increase the surface area of the material [1]. Our focus is to explore the self doping behavior of acid functionalised PAni nanofibres. Functionalisation is achieved by a quick and scalable reflux process [2,3]. Carboxylic acid side-groups can be attached and these groups act to self-dope the polymer nanofibres. Using this technique the stability of the material improves, whilst simultaneously maintaining its ability to switch between different forms displaying distinctly different properties. The resulting material is characterised using electron microscopy, nuclear magnetic resonance and a range of spectroscopic techniques. The techniques used both confirm the covalent attachment of functional side-groups and also reveal the material to be self-doping. While interesting materials themselves these functionalised PAni nanofibres are also attractive as molecular scaffolds for building new more innovative derivatives that retain the nanostructure and characteristics of Pani while improving its selectivity. [1] J.X Huang, S, J.Am.Chem.Soc.125 (2003), 314-315. [2] E.Lahiff, Synth. Met. 159 (2009), 741-748. [3] E. Lahiff, D. Diamond, International Journal of Nanomanufacturing, Vol. 5, (2010).