Dimanganese trioxide (Mn2O3) based label-free electrochemical biosensor for detection of Aflatoxin-B1.

This work presents, a manganese oxide nanoparticles (Mn2O3nps) based electrochemical immunosensor for the detection of Aflatoxin-B1 (AFB1). X-ray diffrraction spectroscopy study confirms the purely synthesized Mn2O3nps with an average crystallite size of 31.5 nm. Transmission electron microscopy study confirms average particle size of 45 nm. To fabricate an electrochemical biosensor, a thin film of Mn2O3nps was fabricated onto indium tin oxide (ITO) surface using electrophoretic technique. Such fabricated thin film was utilized to immobilize antibodies (Anti-AFB1) for the selective detection of AFB1 using differential pulse voltammetry technique. Prior to perform sensing, bovine serum albumin (BSA) was utilized to block the uncovered sites on the Anti-AFB1/Mn2O3/ITO immunoelectrode surface. The response of BSA/Anti-AFB1/Mn2O3/ITO immunoelectrode was measured as a function of AFB1 in a linear detection range of 1 pg mL-1 to 10 µg mL-1 and sensor showed highest sensitivity of 2.044 μA mL ng-1cm-2 with lower detection limit of 0.54 pg mL-1. A spiked sample response of corn extract was studied in the linear range of 1 pg mL-1 to 10 µg mL-1 and immunoelectrode (BSA/Anti-AFB1/Mn2O3/ITO) showed recovery rate of 98.6 %.