Abstract: The multilayer films of horseradish peroxidase (HRP) were fabricated by layer-by-layer assembly of HRP and concanavalin A (Con A) through lectin-glycogen reaction. The surface topography and roughness were characterized by AFM. The thickness of the films was studied by AFM and ellipsometry. The thicknesses of the Con A and the HRP film are about 9.0 and 4.6 nm, respectively, which correspond to their X-ray diffraction data. It is demonstrated that the shape of Con A and HRP molecule was well retained during the assembly process. Cyclic voltammetry (CV) was used to test the electrochemical properties of the films. The enzyme electrode of three bilayers of （Con A/HRP） films was sensitive for the reduction of hydrogen peroxide in the methylene blue (MB) solution. The response current is proportional to the concentration of H2O2 within the range of 0.2～1.0 mmol•L－1. The sensitivity of the enzyme electrode is 24.0 mA•mol－1 •L and the apparent Michaelis constant is 4.2 mmol•L－1.

Key words: HRP, Con A, Surface topography, Assembly film, AFM, Enzyme electrode