In this study, a bismuth film was used as a sensing platform for immunoreaction assay which includes the interactions between IgE and anti-IgE molecules. For preparing this assay, IgE was deposited on a carbon paste electrode via bismuth(III) cations without using any membrane or functional reagent. The immobilized reagents and interaction of anti-IgE on this formation were monitored by using atomic force microscopy technique and electrochemical impedance spectroscopy. Then some experimental parameters like the effect of IgE amount and the IgE anti-IgE interaction time were optimized. Under the optimal experimental conditions, the binding of anti-IgE was also examined by following current decrease in differential pulse voltammograms of neutral red.