Hematite‐Reduced Graphene Oxide Nanocomposite‐Based Electrochemical Biosensing Platform for Rapid Detection of Fumonisin B1 in Corn Samples

Naturally occurring mycotoxins present significant health risks to humans and animals due to their toxic and carcinogenic properties, often contaminating food supplies. Therefore, the development of a highly sensitive and selective detection method for mycotoxins is essential. In this study, we report an electrochemical biosensing platform for the detection of the most abundant mycotoxin, fumonisin B1 (FB1), using a nanocomposite of hematite (α‐Fe 2 O 3 ) and reduced graphene oxide (rGO) nanosheets. The successful synthesis of the α‐Fe 2 O 3 /rGO nanocomposite was validated using various characterization techniques, including x‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), Raman spectroscopy, and high resolution transmission electron microscopy (HR‐TEM). A smooth, uniform, and thin layer of α‐Fe 2 O 3 /rGO was successfully deposited onto an indium tin oxide (ITO) glass substrate using the electrophoretic deposition (EPD) process. Subsequently, anti‐FB1 antibodies (ab‐FB1) were covalently immobilized onto the α‐Fe 2 O 3 /rGO/ITO surface using EDC–NHS chemistry enabling the fabrication of a stable immunoelectrode for biosensing applications. To block nonspecific binding sites, the immunoelectrode was treated with bovine serum albumin (BSA). The biosensor exhibited a decreasing electrochemical response with increasing concentrations of FB1 in the range of 1 × 10 −3 –700 ng mL −1 , with a limit of detection (LOD) of 0.0052 ng mL −1 . The fabricated BSA/ab‐FB1/α‐Fe 2 O 3 /rGO/ITO biosensor demonstrated a sensitivity of 6.36 µA mL ng − 1 cm − 2 and a high correlation coefficient ( R 2 = 0.98831). When the fabricated immunoelectrode was tested with spiked sweet corn samples, satisfactory percentage recovery values were achieved in the range of 97.2% to 99.4%, indicating its excellent analytical performance andpotential applicability for real‐sample biosensing analysis.