▎ 摘　　要

To fabricate the aflatoxin B-1 immunosensor, graphene oxide, 2,5-di-(2-thienyl)-1-pyrrole-1-(p-benzoic acid) and chloroauric acid were electrodeposited on the gold electrode surface in sequence. Then aflatoxin B-1 (AFB(1)) antibody was covalently connected to the conducting polymer film with 1-ethyl-(3-dimethyl-aminopropyl)-carbodimide/N-hydroxysuccimimide (EHC/NHS) as activator and 1,3-dibutyliminazolium hexafluorophosphate ionic liquid was finally coated on the modified electrode. The Fe(CN)(6)(3-/4-) phosphate buffer solution (pH 7.0) was employed as base solution for investigating electrochemical performances of the immunosensor by cyclic voltammetry and electrochemical impedance spectroscopy. Research revealed the introduction of graphene and gold nanocomposite obviously improved electron transfer rate of the modified layer, and the apparent electroactive surface areas of the electrode also increased up to 0.2188 cm(2) and 0.2640 cm(2) from 0. 1772 cm(2) of bare gold electrode, respectively. When aflatoxin B-1 concentration is in the range of 3.2 x 10(-15) -3.2 x 10(-13) mol/L, the electron transfer impedance responses of the sensor will linearly increase. The correlation coefficient (R-2) and the detection limit were found to be 0.994 and 1.1 x 10(-15) mol/L. The electrochemical response of the immunosenor can keep almost constant after stored at 4 degrees C for 20 weeks. Sensitivity and stability of the proposed method are better than those of other methods reported in literatures, it has been successfully applied to determination of trace AFB(1) in peanut samples.