A chemiluminescence enhancer; acts as an electron transfer mediator, reacting with HRP-II to release HRP and a PTZ-343 radical which oxidizes luminol anions to induce light emission; increases HRP-induced chemiluminescent light emission by >800% ; enhances soybean peroxidase-induced chemiluminescence, increasing sensitivity and lowering the detection limit from 1.1 to 0.18 pM