A novel and green CTAB-functionalized graphene nanosheets electrochemical sensor for Sudan I determination

Hexadecyl trimethyl ammonium bromide (CTAB)-functionalized graphene nanosheets were synthesized by using a mild and green method and characterized by several techniques, including Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction spectroscopy and electrochemical impedance spectroscopy. These CTAB-functionalized graphene nanosheets were used as the modified material on electrode to determine Sudan I, which remarkably increased the electrochemical response of Sudan I compared to that on glassy carbon electrode. This increase in electrochemical response is attributed to the long hydrophobic chain in CTAB which facilitates the accumulation of Sudan I and the unique physiochemical properties of graphene nanosheets which also promote the electrochemical response of Sudan I. With the optimized experimental conditions, the anodic peak currents of Sudan I are proportional to its concentration in the range of 0.002-8.0 μmol L−1 and 8.0-100.0 μmol L−1, and the limit of detection of 0.7 nmol L−1 is obtained. This electrochemical sensor shows good repeatability, reproducibility and is successfully applied in the determination of Sudan I in real food samples.