A demonstration that o2− is a crucial intermediate in the high quantum yield luminescence of luminol

The chemiluminescence of luminol, due to its reaction with alkaline H₂O₂, is inhibited by Superoxide dismutase or by hydroxyl radical scavengers. Hematin markedly enhances this H₂O₂-induced luminescence of luminol and lessens, but does not eliminate, the sensitivity towards these inhibitors. Reaction mechanisms are proposed to account for these results. Since luminol luminescence depends upon a reaction between the luminol radical and O₂⁻, and since the luminol radical can reduce dioxygen to O₂⁻, Superoxide dismutase-inhibitable luminol luminescence cannot be reliably used as a detector of O₂⁻ production.