Novel amperometric bisphenol A (BPA) sensors were fabricated by covalently bonding polyamidoamine (PAMAM) dendrimers layer-by-layer onto a gold electrode on quartz crystal substrate using a peptide chemical protocol. Au electrodes was pretreated with 3-mercaptopropionic acid (MPA) and further reacted with generation 5 amine-terminated PAMAM dendrimer (G5-NHusing -(3-dimethylaminopropyl)--ethylcarbodiimide hydrochloride (EDC) as the peptide coupling reagent. The BPA-sensing film thus prepared was characterized by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). The effects of the intermediate layer, the generations (sizes) of PAMAM dendrimer and the concentration of PAMAM dendrimer on the BPA sensing properties (response) of the sensors were investigated to optimize the fabrication of the modified electrodes. Furthermore, factors that affected the detection processes were optimized. The BPA sensor that was based on the G5-NH-MPA/Au electrode exhibited a high response, satisfactory linearity, a low detection limit and favorable long-term stability.