Voltammetric determination of Aflatoxin B1 using a bismuth layer-gold nanoparticles modified glassy carbon electrode

Abstract This work describes the development of an electroanalytical methodology for the direct determination of Aflatoxin B1 using a surface-modified vitreous carbon electrode with a bismuth film and gold nanoparticles. Cyclic voltammetry was used to determine the electrochemical behavior of Aflatoxin B1 on the working electrode. A well-defined cathodic wave was observed in the voltammogram which is associated with the direct reduction of Aflatoxin B1, so this signal was selected as the analytical response. To maximize this response, Square Wave Voltammetry was selected as the quantitative technique; then, pulse frequency, pulse amplitude, and potential step were optimized using a Box-Behnken surface design. A calibration curve was constructed in an interval of concentrations from 1 to 200 ngL− 1 with different Aflatoxin B1 standards; with the proper statistical analysis, it was found a linear range of 37.31 to 100 ngL− 1, with a limit of detection of 5.71 ng L− 1, and a sensitivity of 0.033 µA ngL− 1. A relative standard deviation percentage of 4.28 was obtained in the repeatability study. Finally, the proposed methodology was successfully used to analyze commercial milk samples.