Disposable label - Free immunosensor on screen - Printed electrodes for the detection of Aflatoxin B1 in food

An impedimetric label - free immunosensor on disposable screen-printed carbon electrode (SPCE) for Aflatoxin B1 detection has been developed in this work. SPCE surface was modified with gold nanoparticles and the monoclonal anti-AFB1 was immobilized on the working electrode through a cysteamine layer. After each coating step, the modified surface was characterized by Cyclic Voltammetry and Electrochemical Impedance Spectroscopy. The charge transfer resistance (Rct) was chosen as the best parameter that describes the reproducible change in electrical properties of the electrode surface at different AFB1 concentrations and it was used to investigate the analytical parameters of the developed immunosensor. Under optimized conditions, the immunosensor showed a linear relationship between 0.01 and 4 ng/mL with a low detection limit of 0.01 ng/mL, making it suitable to detect AFB1 amount in many common food products. Lastly, the immunosensor was used to measure AFB1 in nuts samples with good results.