β-cyclodextrin non-covalently modified ionic liquid-based carbon paste electrode as a novel voltammetric sensor for specific detection of bisphenol A

A highly effective approach was developed for specific detection of bisphenol A (BPA) in real samples, based on a beta-cyclodextrin (beta-CD) modified ionic liquid-based carbon paste electrode (beta-CD/ILCPE). Voltammetry and electrochemical impedance spectroscopy measurements reveal significantly improvements in the conductivity and compatibility of the sensor, when using an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) as a super conductive binder in the composition of carbon paste. The introduction of beta-CD as a modifier as well as a host molecule exhibited obviously enhanced sensitivity and selectivity toward BPA over a wide concentration range of 1.0 x 10(-7) to 1.1 x 10(-5) mol L-1, with a detection limit (S/N = 3) of 8.3 x 10(-8) mol L-1. Compared to classic carbon paste electrodes, the BPA sensor not only possesses the inherent reusability and cost effectiveness, but also shows better sensing performance and stability. This can be attributed to the combination of the high ion conductivity and non-covalently interaction properties of BMIMBF4, and the supramolecular recognition and enrichment capability of beta-CD. The mechanism of electrode processes was also presented. The proposed sensor was successfully used in the determination of BPA in real samples with good recovery. (C) 2013 Elsevier B.V. All rights reserved.