A novel electrochemical immunosensor based on AuNPs/N-G@PANI@CS was constructed for the highly sensitive and selective detection of mycotoxin FB1 in food

Fumonisin is a mycotoxin produced by secondary metabolites of fungi, which not only damages the immune system but also elevates the risk of cancer. Therefore, the development of convenient, efficient and accurate methods for detecting fumonisin B1 (FB1) is of great significance for protecting the food from the damage of FB1 toxins. In this study, we utilized chitosan functionalized nitrogen-doped graphene and polyaniline (N-G@PANI@CS) as electrode modification materials, and electrodeposited gold nanoparticles (AuNPs) onto the electrode surface to construct an electrochemical immunosensor for the detection of mycotoxin FB1 in food. Under optimal conditions, the immunosensor exhibited a strong linear response in the range of 0.50 ng/mL-800.00 ng/mL. The curve equation was Ipa (μA)= -6.127 ×LogCFB1+ 57.851 (R2=0.992), with a limit of detection (LOD) of 0.07 ng/mL and a limit of quantitation (LOQ) of 0.22 ng/mL. Furthermore, the relative standard deviation (RSD) of the constructed electrochemical immunosensor in actual corn samples was 3.26 %-4.73 %, and the recovery rate was 93.97 %-98.62 %, which can be used for the detection of FB1 in the actual corn samples, and the sensor also showed high specificity and stability. This study provides a novel, reliable and convenient means for the detection of FB1 in contaminated food. [Display omitted] •An electrochemical immunosensor for food mycotoxin FB1 was developed.•AuNPs/N-G@PANI@CS had strong conductive and FB1-binding traits.•The immunosensor exhibited a broad linear range and low detection limit for FB1 detection.