Sensitive Voltammetric Determination of Vanillin with an Electrolytic Manganese Dioxide−Graphene Composite Modified Electrode

Abstract

The electrolytic manganese dioxide - graphene (EMDG) composite was used in the construction of a sensor, which showed strong electrocatalytic activity to the oxidation of vanillin in neutral solutions. Vanillin produces an anodic peak at about 0.67 V at this electrode. Several electrochemical parameters of these processes were further carefully calculated with the results of the charge transfer coefficient α as 0.703 and the electron transferred number n as 2. The electrocatalytic behavior was further exploited as a sensitive detection scheme for the vanillin determination by differential-pulse voltammetry (DPV). Under optimized conditions, the anodic peak current increased linearly with the vanillin concentration over the range from 1.0×10-7 to 4.5×10-5 mol L-1. The detection limit was calculated as 3.2×10-8 mol L-1 (S/N=3). The proposed method was applied to the detection of biscuits and chocolates samples with satisfactory results.