▎ 摘　　要

Alpha fetoprotein (AFP) is a specific tumor marker for the diagnosis of primary liver cancer. In this work, a molecularly imprinted (MIP) electrochemical sensor for AFP was prepared by surface imprinting method. The MIP electrochemical biosensor uses polysulfide cordial and graphene-gold composite as electrode modified nanomaterials to effectively enhance the detection of electrical signals. Dopamine (DA) is the functional monomer and the PDA-AFP complex is obtained by electropolymerization. The eluent elutes the functional monomer and the specific cavity formed can adsorb the target molecule. Under optimal experimental conditions, differential pulse voltammetry (DPV) was used for detection. The current of the prepared biosensor decreases with increasing AFP concentration. The peak current value of DPV assay showed good linearity with the logarithm of AFP concentration in the range of 0.01 ng/mL-1000 ng/mL. The detection limit can reach 3.7 pg/mL.