Stripping measurements of hydrogen peroxide based on biocatalytic accumulation at a horseradish peroxidase/ferrocene/carbon paste electrode

Carbon paste electrodes containing horseradish peroxidase and ferrocene accumulate charge in the presence of hydrogen peroxide, the discharge of which gives the chronoamperometric stripping current. Hence a 50-fold enhancement of the response for 50 nM hydrogen peroxide is obtained following 60s preconcentration. The hydrogen peroxide measurements were made in 0.05 M phosphate buffer of pH 7.4. The relative standard deviation at the 50 nM level is 9.8%. The electrode is useful for hydrogen peroxide determination for more than two days.