Electrochemical sensor for determination of aflatoxin B based on multiwalled carbon nanotubes-supported Au/Pt bimetallic nanoparticles.

A sensitive and selective imprinted electrochemical sensor for the determination of aflatoxin B (AFB) was constructed on a glassy carbon electrode by stepwise modification of functional multiwalled carbon nanotubes (MCNTs), Au/Pt bimetallic nanoparticles (Au/PtNPs), and a thin imprinted film. The fabrication of a homogeneous porous poly o-phenylenediamine (POPD)-grafted Au/Pt bimetallic multiwalled carbon nanotubes nanocomposite film was conducted by controllable electrodepositing technology. The sensitivity of the sensor was improved greatly because of the nanocomposite functional layer; the proposed sensor exhibited excellent selectivity toward AFB owing to the porous molecular imprinted polymer (MIP) film. The surface morphologies of the modified electrodes were characterized using a scanning electron microscope. The performance of the imprinted sensor was investigated by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy in detail. A linear relationship between the sensor response signal and the logarithm of AFB concentrations ranging from 1 × 10 to 1 × 10 mol L was obtained with a detection limit of 0.03 nmol L. It was applied to detect AFB in hogwash oil successfully. [ABSTRACT FROM AUTHOR]