Enzyme catalytic resonance scattering spectral detection of trace hydrogen peroxide using guaiacol as substrate

Abstract

Hydrogen peroxide oxidized guaiacol to form tetramer particles that exhibited a strong resonance scattering (RS) peak at 530 nm in the presence of horseradish peroxidase (HRP) in citric acid-Na₂HPO₄ buffer solution of pH 4.4. The RS peak increased when the concentration of hydrogen peroxide increased. The increased RS intensity (ΔI_{530 nm}) was linear to the hydrogen peroxide concentration in the range of 0.55-27.6 μM, with a linear regression equation of ΔI_{530 nm} = 17.1C + 1.6, a relative coefficient of 0.9996 and a detection limit of 0.03 μM H₂O₂. This proposed method was applied to detect hydrogen peroxide in rain water, with sensitivity, selectivity, rapidity, and recovery of 98.0-104 %.

KEY WORDS: HRP, H₂O₂, Guaiacol, Resonance scattering spectral method

Bull. Chem. Soc. Ethiop. 2011, 25(2), 161-168.