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 B-1 (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 alpha-naphthyl phosphate, which produced electrochemical signal. Under optimized conditions, this method could detect FB1 from 0.01 to 1000 ngmL(-1) with a detection limit of 2 pgmL(-1). This is well below the detection limit required from European Union legislation, 2-4 mgL(-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.