A method to detect beta-lactoglobulin (BLG) is described. The method includes the steps of adding a known concentration of hydrogen peroxide to a sample known to, or suspected of containing BLG; and electrolyzing the sample using a working electrode at a fixed potential sufficient to electrolyze BLG, and measuring a current signal within the sample. A diminution of the current signal in the sample as compared to a corresponding current signal from a standard solution containing a known concentration of hydrogen peroxide and no BLG indicates that the sample contains BLG.