Human disease processes are often characterized by a deviation from the normal physiological concentration of critical biomarkers. The detection of disease biomarkers requires the development of novel sensing methods which are sensitive, specific, efficient and low-cost. To address this need, the ability of a device, which incorporates a film of polymer acid doped polyaniline, to respond to proteins at physiological pH and ionic strength was assessed. The conductive polymer was found to respond by changing conductivity in the presence of biomolecules, demonstrating a direct chemical to electronic transduction method. In future work, specificity can be incorporated into the system by integrating the conductive polymer with a protein selective film. The demonstration of a conductive polymer which is responsive to proteins at physiological conditions is a step towards the integration of these materials into implantable sensing systems.