Determination of horseradish peroxidase and a peroxidase-like iron porphyrin at a Nafion-modified electrode

摘要

A catalytic coupling reaction between 4-amino antipyrine and a N,N-disubstituted aniline derivative has been exploited in the indirect electrochemical detection of horseradish peroxidase (HRP) and of a biomimetic catalyst,the iron(III) sulfonated tetraphenyl porphyrin.In the presence of hydrogen peroxide and one of the two catalysts a cationic electroactive quinone-iminium dye P~+ was formed and detected by linear scan voltammetry using a screen-printed electrode coated with a Nafion film.Detectio nlimits of 10~(-12) M for HRP and 4x10~(-10)M for the iron porphyrin have been achieved.In conclusion the iron porphyrin is considered to be a promising alternative to the HRP label in enzyme immunoassarys with electrochemical detection.