Electrochemical immunosensor based on Au-NPs/Fe2O3/CeO2 nanocomposite for aflatoxin B1 detection

• A novel Au-NPs/Fe 2 O 3 /CeO 2 nanocomposite applied as a transducer material for electrochemical sensing performance. • An ultrasensitive electrochemical immunosensor for Aflatoxin B1. • Au-NPs, redox activity of Fe 2 O 3 , and oxygen storage/release capacity of CeO 2 , facilitating improved electron transfer kinetics. • The immunosensor demonstrated a low limit of detection (LOD with a wide linear detection range. Even at trace levels, aflatoxin B 1 (AFB 1 ) is a highly poisonous and carcinogenic mycotoxin that poses major concerns to human health and food safety. This work describes the creation of a unique Au-NPs/Fe 2 O 3 /CeO 2 nanohybrid that combines the superior electrical conductivity of gold nanoparticles with the catalytic and redox characteristics of cerium–iron oxides in order to answer the pressing demand for sensitive and dependable detection. XRD, FTIR, BET, SEM, XPS, cyclic voltammetry, and electrochemical impedance spectroscopy were used to thoroughly characterize the structural, morphological, and electrochemical characteristics of the produced nanocomposite. With a wide linear range of 10–50 ng/mL, a low detection limit of 0.1 ng/mL, high sensitivity, acceptable repeatability, and consistent performance over 18 days, the resulting immunoelectrode allowed for label-free impedimetric detection of AFB 1 . These results demonstrate the strong potential of the proposed nanohybrid-based biosensor for practical food safety monitoring and real-world toxin detection applications.