Electrochemical sensor for determination of aflatoxin B1 based on multiwalled carbon nanotubes-supported Au/Pt bimetallic nanoparticles

Abstract

A sensitive and selective imprinted electrochemical sensor for the determination of aflatoxin B1 (AFB1) 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 AFB1 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 AFB1 concentrations ranging from 1 × 10−10 to 1 × 10−5 mol L−1 was obtained with a detection limit of 0.03 nmol L−1. It was applied to detect AFB1 in hogwash oil successfully.