Investigation on the potential use of the mimetic peroxidase-catalyzed reaction of hydrogen peroxide and o-hydroxyphenylfluorone in fluorescence analysis

The reaction between o-hydroxyphenylfluorone (HPF), a common fluorescence dye, and hydrogen peroxide catalyzed by mimetic peroxidase iron-tetrasulfonatophthalocyanine (FeTSPc) has been adapted to the determination of trace amounts of H₂O₂, FeTSPc and FeTSPc-mouse immunoglobulin G (IgG) conjugate. In the case of catalysis with FeTSPc, trace amounts of H₂O₂ can quench the fluorescence of HPF rapidly and significantly. Under optimum conditions, the logarithm value of fluorescence quenching (log(F₀/F)) was linear over the range of 0.0-1.0x10^-7mol/l H₂O₂, 0.0-9.0x10^-8mol/l FeTSPc and 0.0-8.0x10^-8mol/l FeTSPc-IgG conjugate, with the detection limits of 7.5x10^-10mol/l H₂O₂, 7.0x10^-10mol/l FeTSPc and 2.6x10^-10mol/l FeTSPc-IgG conjugate, respectively. The catalytic activity of FeTSPc increased by more than three times when it was labeled to IgG. The feasibility of applying the catalyzed system in the environmental detection of trace amounts of H₂O₂ was also studied. The proposed FeTSPc-catalyzed system was concluded as being suitable for both H₂O₂ determinations and mimetic enzymatic immunoassays. Copyright (C) 2000 Elsevier Science B.V.