There is a large potential market for biosensors in the clinical and health care fields and for industrial process monitoring. Often bio-sensors require expensive equipment and procedures that are confined to the skilled operator and thus are unsuitable for many purposes outside the analytical laboratory. A novel signal transduction method is described that could lead to simplified monoclonal antibody-based immunosensors. This approach is oriented towards a technique that measures changes in resistance that occur in ultra-thin metal films when an antibody-antigen interaction takes place at the thin-film surface.Commercial Applications:Applications will be to numerous aspects of clinical health care, animal husbandry, industrial process monitoring and environmental control.