Carboxylated multiwalled carbon nanotubes based biosensor for aflatoxin detection

Abstract

We report results of studies relating to the development of an electrochemical immunosensor based on carboxylated multiwalled carbon nanotubes (c-MWCNTs) electrophoretically deposited onto indium tin oxide (ITO) glass. This c-MWCNTs/ITO electrode surface has been functionalized with monoclonal aflatoxin B1 antibodies (anti-AFB1) for the detection of aflatoxin-B1 using electrochemical technique. Electron microscopy, X-ray diffraction and Raman studies suggest successful synthesis of c-MWCNTs and the Fourier transform infra-red spectroscopic (FT-IR) studies reveal its carboxylic functionalized nature. The proposed immunosensor shows high sensitivity (95.2 μA ng-1 mL cm-2), improved detection limit (0.08 ng mL-1) in the linear detection range of 0.25-1.375 ng mL-1. The low value of association constant (0.0915 ng mL -1) indicates high affinity of immunoelectrode towards aflatoxin (AFB1). © 2013 Elsevier B.V.