ELECTROCHEMICALLY OXIDIZED FERROCENES AS CATALYSTS FOR THE CHEMILUMINESCENCE OXIDATION OF LUMINOL

Electrochemically oxidized ferrocene and eleven ferrocene derivatives were investigated as catalysts for the chemiluminescent oxidation of l uminol by hydrogen peroxide. The catalytic effect has been related to the redox potential of the ferrocenes. The effect of twelve different buffers with different pK(a) values and four different electrode mater ials was also investigated. A combination of ferrocenedicarboxylic aci d, bis tris propane buffer and an ITO electrode gave the most intense light emission and eliminated measurable electrogenerated background c hemiluminescence. Phenol labelled with ferrocenemonocarboxylic acid vi a a peptide bond catalyzed more intense chemiluminescence than the par ent ferrocene derivative. Results were used to suggest a structure for ferrocene labelled antigens that can be used in competitive immunoass ays. (C) 1998 Elsevier Science S.A. All rights reserved.