In acetate acid buffer solution, horseradish peroxidase (HRP) catalyzed H2O2 oxidation of excess I－ to form , and combined with cationic surfactant (CS) such as tetradecyl dimethylbenzyl ammonium chloride (TDMAC), dodecyl dimethylbenzyl ammonium chloride (DDAC), cetyltrimethyl ammonium bromide (CTAB), octadecyl dimethyl benzyl ammonium chloride (ODAC), cetylpyridinium chloride (CPC), dodecyl pyridinium chloride (DPC) and tetrabutyl ammonium iodide (TBAI) to produce TDMAC-I3, DDAC-I3, CTAB-I3, ODAC-I3, CPC-I3, DPC-I3 and TBAI-I3 association particles, respectively, that exhibited the strongest resonance scattering peak at 468 nm. The H2O2 concentration in the range of 0.17×10－7～173×10－7, 0.432×10－7～173×10－7, 1.73×10－7～259×10－7, 1.73×10－7～86.4×10－7, 1.73×10－7～216×10－7, 0.86×10－7～259×10－7 and 0.86×10－7～86.4×10－7 mol•L－1, was linear to the intensity at 460 nm, with a detection limit of 0.86×10－8, 2.2×10－8, 8.6×10－8, 4.6×10－8, 3.6×10－8, 4.3×10－8 and 4.4×10－8 mol•L－1, respectively. The TDMAC resonance scattering spectral method was used to the determination of H2O2 in real samples, with satisfactory results.

Key words: H2O2, horseradish peroxidase, cationic surfactant, catalytic-resonance scattering assay