Aurothiomalate as an electroactive label for the determination of immunoglobulin M using glassy carbon electrodes as immunoassay transducers

For both immunoassay formats, calibration curves in the range of 7.5 × 10−11 to 1.0 × 10−9 M of IgM were obtained with an estimated detection limit of 2.8 × 10−11 M (25 ng/ml). Moreover, the levels of IgM in synthetic serum were evaluated, applying the method of standard additions following both formats competitive and non-competitive. These samples were previously pretreated in order to remove most of the albumin and IgG, which interfered in the electrochemical detection.