Sensitive and Efficient Electrochemical Determination of Kojic Acid in Foodstuffs Based on Graphene-Pt Nanocomposite-Modified Electrode

Abstract

A differential pulse voltammetric (DPV) method for the determination of kojic acid was developed. Glassy carbon (GC) electrode was modified with composite nanomaterials of graphene (GR) sheets and platinum (Pt) nanoparticles. Electrochemical behavior of kojic acid on the electrode was studied, which indicated that the nanocomposite-modified electrode could efficiently promote electrocatalytic oxidation of kojic acid based on synergistic effect of excellent electrical conductivity and high catalytic activity of GR and Pt. A rapid, sensitive, and simple electrochemical method was then developed for determination of kojic acid using the constructed electrode. Under the optimized conditions, the oxidation peak current exhibited a wide linear range from 0.2 to 1,000 μM towards the concentration of kojic acid with a sensitivity of 139.3 μA mM−1, and the limit of detection was as low as 0.2 μM. The modified electrode was also used for quantitative analysis of kojic acid in food samples, and the recoveries were between 97.5 and 101.3 %, indicating feasibility of the electrochemical method for kojic acid analysis in routine detection. In view of optimization and validation results as well as applicability to real samples, this method could be considered as a good alternative for routine analysis of kojic acid in foodstuffs.