Graphene oxide-Mn₃O₄nanocomposites for advanced electrochemical biosensor for fumonisin B1 detection

Occurrence of mycotoxins in food samples threat to its safety issue due to the presence of high toxicity and carcinogenic behavior, thus requiring highly sensitive and selective detection. Herein, the trimanganese tetraoxide (Mn₃O₄) nanoparticles in combination with graphene oxide (GO) nanocomposite were used to enhance the electrochemical performance for fabrication of electrochemical biosensor for fumonisin B1 (FB1) detection. The various characterization tools were used to validate the fabrication of GOMn₃O₄nanocomposites. To fabricate the electrochemical biosensor on an indium tin oxide (ITO) coated glass substrate, a thin film of GOMn₃O₄nanocomposite was prepared using electrophoretic deposition technique, and antibodies (ab-FB1) were immobilized onto the electrode for selective FB1 detection. The differential pulse voltammetry technique was used to observe the sensing performance. The non-binding sites of the ab-FB1 on the immunoelectrode were blocked with bovine serum albumin (BSA). The biosensor electrode was fabricated as BSA/ab-FB1/GOMn₃O₄/ITO for the detection of FB1. The sensitivity of the biosensor was obtained as 10.08μA ml ng^-1cm^-2in the detection range of 1 pg ml^-1to 800 ng ml^-1with a limit of detection of 0.195 pg ml^-1. In addition, the recovery of BSA/ab-FB1/GOMn₃O₄/ITO immunoelectrodes was also performed on sweet corn samples and is calculated to be 98.91%.