Highly efficient and selective quantification of vanillin in food, beverages and pharmaceuticals using surfactant modified carbon paste sensor

Abstract

The rampant use of vanilla has severe ramifications on our health. Federal Office of Public Health has placed restrictions on use of Vanillin (VAN) in baby food. Our aim was to prepare a sensor for the swift determination of VAN in food essence, non-alcoholic beverages, food supplements and pharmaceutical formulations. A modified carbon paste electrode drop cast with cetyltrimethylammoniumbromide (CTAB) was designed and scrutinized by cyclic and differential pulse voltammetry techniques. Surface morphology was studied using Field emission scanning electron microscopy (FE-SEM), the elemental composition by Energy Dispersive X-rays (EDX), and charge transfer kinetics by Electrochemical Impedance Spectroscopy (EIS). A significant decline of 153 mV in anodic overpotential with an impressive eight-fold enhancement of current indicates better electrocatalytic kinetics at the modified electrode. The calibration curve exhibited linearity over a wide range of 8 × 10−8 to 3 × 10−3 M, with a limit of detection 0.23 nM (S/N = 3). The selectivity of the fabricated sensor towards VAN in the presence of 1000-fold excess of common interferants such as ferulic acid, folic acid, tryptophan, and uric acid was noteworthy.