Monitoring the heme iron state in horseradish peroxidase to detect ultratrace amounts of hydrogen peroxide in alcohols.

Despite the importance of hydrogen peroxide (HO) in initiating oxidative damage and its connection to various diseases, the detection of low concentrations of HO (<10 μM) is still limited using current methods, particularly in non-aqueous systems. One of the most common methods is based on examining the color change of a reducing substrate upon oxidation using UV/Vis spectrophotometry, fluorophotometry and/or paper test strips. In this study, we show that this method encounters low efficiency and sensitivity for detection of ultratrace amounts of HO in non-aqueous media.