Development of Biosensor for Detection of Thrombin in Blood by Polyaniline Nanofibers Conducting polymers have always been a fascinating set of materials for researchers over the years. Their versatility in application makes them unique along with their easy processing techniques and low cost. Polyaniline is one of the most important members of this family. It has been widely used for various applications like corrosion resistance, EMI shielding, sensor development etc. Gas sensors and bio sensors have been developed by a lot of researchers having the basic working block as polyaniline. The ease of processing of polyaniline and its capability to encapsulate bio molecules within has made it an even better option for bio sensor development. This project aims at developing a new bio sensor making use of polyaniline as the base block for the detection of thrombin. Thrombin is a protease in the body that is responsible for thrombosis or excessive blood clotting. This is a study to try and crosslink polyaniline with glutaraldehyde and then covalently bond with a thrombin specific substrate. The cleavage of thrombin on the substrate will change the internal resistance of polyaniline and also be detectable in blood i.e. liquid media with the cleaved substrate molecules. Polyaniline nano wires prepared by electrospinning have been used to enhance the sensor performance and reduce the sample required for testing. The polyaniline nano wires are hybrid nano wires prepared by using cellulose acetate as the binder for polyaniline. SEM and EDAX analysis were carried out for the Polyaniline/cellulose acetate films to thoroughly understand the structure of these films. The electrical resistance measurements were noted to get the basic concept of the bio sensor working. This biosensor when fully developed will be a disposable biosensor for detecting thrombin in blood.