Graphite Furnace Atomic Absorption Spectrophotometric Determination of Trace Horseradish Peroxidase Using Nanosilver

In pH 4.2 HAc-NaAc buffer solution, horseradish peroxidase (HRP) catalyzed H2O2 oxidation of nanosilver to form Ag+. After centrifugation, Ag+ in the supernatant can be measured by graphite furnace atomic absorption spectrophotometry (GFAAS) at the silver absorption wavelength of 328.1 nm. When HRP concentration increased, the Ag+ concentration in the supernatant increased, and the absorption value enhanced. The HRP concentration in the range of 0.84-50 ng.mL(-1) was linear to the enhanced absorption value (Delta A), with a regression equation of Delta A = 0.012C + 0.11, correlation coefficient of 0.9988, and detection limit of 0.41 ng.mL(-1) HRP. The proposed GFAAS method was used to detect HRP in waste water samples, with satisfactory results.