In this Project an introduction and further theoretical description of Surface Plasmon Resonance (SPR) is presented. A matlab program has been written for a theoretical model of a multilayer SPR surface, and this is utilised for investigation of the succes of antibody immobilisation. A method for manufacturing SPR surfaces from a polished glass wafer is presented, and a procedure for immobilising antibodies on this surface is presented. This procedure is utilised to create a biosensor against cardiac Troponin I (cTnI), and this sensor is tested. A commercial available SPR chip (Xantec SPR sensor chip CMD500l) is also tested and found to provide more reproducible data. When testet on cTnI diluted in bovine serum albumin, the sensor gives poor results. It is concluded that more experiments with different pH values and different coatings are needed.