Abstract:

Highly stable glucose oxidase(GOx) multilayer films were fabricated on cystamine modified gold electrode surfaces by layer-by-layer self-reaction of periodate-oxidized glucose oxidase. The fabricated process was followed by electrochemical impedance spectroscopy. The experimental results showed that the film was homogeneous and formed in an ordered manner. The gold electrode modified with the GOx multilayers showed excellent electrocatalytical response to the oxidation of glucose when ferrocenemethanol was used as an artificial redox mediator. From the analysis of voltammetric signal, the coverage of active enzyme on the electrode surface was estimated, which had a linear relationship with the number of GOx besides the first layer. This suggested that the analytical performance such as sensitivity, detection limit, and so on, was tunable by controlling the number of the fabricated GOx layer. In addition, the biosensor exhibited a good reproducibility and stability.

Key words: Glucose oxidase; Biosensor; Layer-by-layer self-reaction; Ordered multilayer film; Electrocatalysis