The enzyme catalyzed polymerization of luminol (5-amino-2, 3-dihydroxy-1, 4-phthalazinedione) in the presence of polystyrenesulphonate (SPS) is introduced. Polymerization was achieved using horseradish peroxidase (HRP) as a biocatalyst in a phosphate buffer at pH 8. A green, water-soluble conducting PLUM/SPS complex was obtained. The physico-chemical properties of the product, including possible photoluminescence of the PLUM/SPS complex, were studied. The PLUM/SPS complex was shown to be a chemiluminescent (CL) material that is highly sensitive towards Fe 3+ ions. The quantum yield of the PLUM chemiluminescence was determined to be moderate (0.09 ± 0.01) compared to other chemiluminescent compounds. UV-visible, FTIR, 1 H NMR, GPC and conductivity measurements confirmed that the electroactive form of polyluminol (PLUM) was formed and complexed to the SPS.