Abstract:

An electrochemical immunosensor for the rapid determination of aflatoxin B1 (AFB1) in foods has been fabricated
by employing chitosan, graphene and 1-butyl-3-methyl imidazolium tetrafluoroborate composite film to immobilize AFB1
antibody onto the surface of glassy carbon electrode. Based on the specific immune reaction between AFB1 antibody
and antigen, the effects of immune response on the response current of the immunosensor were investigated by cyclic
voltammetry and differential pulse voltammetry using K3[Fe(CN)6] as the probe in phosphate buffer solution (pH 7.0) with
1 mmol/L K3[Fe(CN)6] and 0.1 KCl. Under the optimized experimental conditions, the reduction in the peak current of
the immunosensor increased with the increase in the logarithm of the concentration of AFB1 in solution, showing a linear
relationship in the AFB1 concentration range of 0.1–8.1 ng/mL with limit of detection (LOD) of 0.04 ng/mL (RSN = 3).
Excellent stability and repeatability of the prepared immunosensor were observed under the selected condition. The recovery
rate of AFB1 in peanut and corn oil samples was in the range of 94.73%–104.41%. The results from this method well agreed
with those obtained by high performance liquid chromatography method, and so it is practicable for the rapid determination
of AFB1 in food.

Key words: immunosensor, aflatoxin B1 (AFB1), graphene, ionic liquid, rapid detection in food safety