Fullerene-MWCNT nanostructured-based electrochemical sensor for the detection of Vanillin as food additive

In this paper, a simple, economical, selective and sensitive electrochemical sensor is proposed for the quantification of vanillin (VAN) in real food samples. It consists of a carbon paste electrode (CPE) nanostructured with Fullerene (FNTs) and functionalized multi-walled carbon nanotubes (f-MWCNTs). The developed electroanalytical method was performed with cyclic voltammetry after optimization of operating conditions, such as supporting electrolytes, pH values and accumulation time. After optimization, the nanostructured sensor showed wide linear responses in the range from 5 x 10(-8) to 9 x 10(-6) mol.L-1 for VAN trace levels and from 10(-5) to 10(-4) mol.L-1 for higher concentrations, with a low detection limit of 3.4 x 10(-8) mol.L-1. For concentrations lower than 10(-5) mol.L-1, VAN was stripped after a previous quick adsorption step (300 s). The f-MWCNTs-FNTs/CPE sensor showed a good stability, repeatability and reproducibility (less than 7 %). This nanostructured sensor was successfully applied to determine VAN concentration as additive in commercial vanilla sugar samples with a satisfactory recovery and a good accuracy (< 6.5 %) in comparison with UPLC/UV control method.