Development of field-deployable instrumentation based on “antigen-antibody” reactions for detection of hemorrhagic disease in ruminants

Development of field-deployable methodology utilizing antigen-antibody reactions and the surface plasmon resonance (SPR) effect to provide a rapid diagnostic test for recognition of the blue tongue virus (BTV) and epizootic hemorrhage disease virus (EHDV) in wild and domestic ruminants is reported. A Spreeta chip, which utilizes microelectronic technology to implement the SPR effect, is shown to possess sufficient sensitivity and operating speed to detect either BTV and EHVD antigens or antibodies in real time. The biosensor consists of an outer active surface layer comprised of either an antibody or antigen immobilized by covalent bonds through several other organic layers including a self assembled monolayer to a gold surface. Parallel experiments were run on the biosensor surface using either a home-built high resolution SPR instrument or a low resolution solid state Spreeta SPR chip. Both instruments were capable of monitoring the antigen-antibody reaction used to selectively detect the presence of BTV and EHDV viral pathogens. Results for the antibody and antigen reactive layers with antigen or antibody solutions as well as the modeling of these layers are discussed. The characteristics of these biosensors - specificity and time of reaction - were assessed. The antibody surface biosensors exhibited a high degree of specificity, even when using low resolution instrumentation. The time of analysis was under 20 min, which was the arbitrary exposure time.