An immunoassay was carried out on disposable oxide-coated silicon chip electrodes made of heavily doped p-type silicon, simply thermally oxidized in room air in a laboratory oven. The present electrode chips allow injection of hot electrons into aqueous electrolyte solutions and can be utilized in detecting electrochemiluminescent labels in fully aqueous solutions. This is demonstrated with an immunoassay of beta(2)-microglobulin using an aromatic Tb(III) chelate as an electrochemiluminescent label. (C) 2016 Elsevier B.V. All rights reserved.