A novel electrochemical aptasensor based on AuNPs-loaded graphene oxide-polyaniline for sensitive detection of aflatoxin B1

In this study, a label-free electrochemical aptasensor for sensitive detection of aflatoxin B1 (AFB1) was created by using a glassy carbon electrode (GCE) with polyaniline-functionalized graphene oxide (GO-PANI) and gold nanoparticles (AuNPs). Various spectroscopic techniques such as UV–Vis spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Zeta potential, and Raman spectra were employed to analyze the morphology and composition of the GO-PANI-Au nanocomposite, confirming its successful preparation. This aptasensor could be used for the detection of AFB1 with a broad linear range of 0.0001 to 50 ng/mL and a low limit of detection (LOD) of 0.0377 pg/mL under the optimized conditions. Furthermore, the constructed aptasensor displayed remarkable selectivity, repeatability, and stability. To validate the practical usability of our aptasensor, we successfully tested it on millet and corn samples, yielding a satisfactory recovery rate of 98.87–106.10% for AFB1 detection. This outcome highlights the potential application of our methodology in real sample analysis. Graphical Abstract A highly efficient and sensitive electrochemical aptamer sensor was successfully developed using GO-PANI-AuNPs nanocomposites, and can be used for the detection of AFB1 with good selectivity, repeatability, and stability.