Development of an immunosensor for the determination of rabbit IgG using streptavidin modified screen-printed carbon electrodes

The immunosensor devices were based on a specific reaction of rabbit IgG with its biotinylated antibodies, which were immobilised on the modified screen-printed carbon electrodes through the streptavidin:biotin reaction. The immunosensors were used for a direct determination of AP labelled rabbit IgG, and for free rabbit IgG detection using a sequential competitive immunoassay. A calibration curve in the range of 5 × 10−11 to 1 × 10−9 M of rabbit IgG was obtained with a estimated detection limit of 5 × 10−11 M (7.0 ng/ml). These immunosensors were stable for 5 months if they were stored at 4 °C.