In this paper,an electrochemical immunosensor for the detection of bisphenol A(BPA) was constructed,based on the preparation of a poly-L-lysine/nano-gold modified electrode by electrodeposition,with disposable screen printed carbon electrode as the substrate.Results showed that,when the dilution factors for the antigen and the primary antibody were 1 000 times,the incubation time for the primary antibody was 60 min,and the pH value for the electrochemical detection environment was 7.4,there existed a good linear relationship between reduction peak current and BPA in the concentration range of 1-250 ng/mL,with a correlation coefficient(r2) of 0.993 and a detection limit of 0.85 ng/mL.With good specificity,reproducibility and stability,this method was applied in the detection of BPA in samples with spiked recoveries of 983%-104%,indicating that the BPA immunosensor has an application potential in the detection of bisphenol A in actual water samples.