Voltammetric detection of bisphenol a by a chitosan-graphene composite modified carbon ionic liquid electrode

In this paper 1-ethyl-3-methylimidazolium tetrafluoroborate based carbon ionic liquid electrode (CILE) was fabricated and further modified with chitosan (CTS) and graphene (GR) composite film. The fabricated CTS-GR/CILE was further used for the investigation on the electrochemical behavior of bisphenol A (BPA) by cyclic voltammetry and differential pulse voltammetry. A well-defined anodic peak appeared at 0.436 V in 0.1 mol/L pH 8.0 Britton-Robinson buffer solution, which was attributed to the electrooxidation of BPA on the modified electrode. The electrochemical parameters of BPA on the modified electrode were calculated with the results of the charge transfer coefficient (alpha) as 0.662 and the apparent heterogeneous electron transfer rate constant (K-s) as 1.36 s(-1). Under the optimal conditions, a linear relationship between the oxidation peak current of BPA and its concentration can be obtained in the range from 0.1 mu mol/L to 800.0 mu mol/L with the limit of detection as 2.64 x 10(-8) mol/L (3 sigma). The CTS-GR/CILE was applied to the detection of BPA content in plastic products with satisfactory results. (C) 2012 Elsevier B.V. All rights reserved.