A Highly Sensitive Electrochemical Immunosensor for Fumonisin B1 Detection in Corn Using Single-Walled Carbon Nanotubes/Chitosan

A sensitive electrochemical immunosensor was developed for detecting fumonisin B1 (FB1) in corn using the single‐walled carbon nanotubes/chitosan. The detection mechanism of immunosensor was based on an indirect competitive binding to a fixed amount of anti‐FB1 between free FB1 and FB1‐bovine serum albumin, which was conjugated on covalently functionalized nanotubes/chitosan laid on the glass carbon electrode. The anti‐rabbit immunoglobulin G secondary antibody labeled with alkaline phosphatase was then bound to the electrode surface through reactisubstrate α‐naphthyl phosphate, which produced electrochemical signal. Under optimized conditions, this method could detect FB1 from 0.01 to 1000 ng mL−1 with a detection limit of 2 pg mL−1. This is well below the detection limit required from European Union legislation, 2–4 mg L−1. Moreover, good recoveries were obtained for the detection of spiked corn samples and actual corn samples. As the method has good sensitivity and recovery for detecting FB1, it is a practical detection method.