Enzyme catalytic resonance scattering spectral detection of trace hydrogen peroxide using guaiacol as substrate
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 (ΔI530 nm) was linear to the hydrogen peroxide concentration in the range of 0.55-27.6 μM, with a linear regression equation of ΔI530 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.