Electrochemical Behavior and Determination of Bisphenol A at ZnO-MWCNTs Composite Modified Electrodes in the Presence of CTAB

KeyWord:bisphenol A  CTAB  DPV  nano ZnO  CNT

Abstract:

      Nano ZnO-MWCNTs was successfully synthesized by hydrothermal method with the assistance of polyethylene glycol£¨PEG£©.A ZnO-MWCNTs composite modified glassy carbon electrode£¨ZnO-MWCNTs/GCE£© was prepared by coating method.The electrochemical behavior of bisphenol A at the modified electrode was investigated by cyclic voltammetry£¨CV£© in the presence of cetyltrimethylammonium bromide£¨CTAB£©.The effects of buffer pH,CTAB concentration and accumulation time on the determination were investigated.The results indicated that bisphenol A showed a good electrochemical response at the modified electrode in pH 7.0 phosphate buffer in the presence of 8ª±0¡Á10-5 mol/L CTAB.The oxidation peak current in CV curves at ZnO-MWCNTs/GCE was 7 times as high as that at the unmodified electrode.CV studies also indicated that the electrooxidation of bisphenol A at the modified electrode was adsorption controlled,and totally irreversible process involved in two electrons and two protons.Under the optimum conditions,the oxidation peak current of bisphenol A in DPV curves was proportional over the concentration range of 5.0¡Á10-8-1.5¡Á10-5 mol/L with a detection limit of 1.0¡Á10-8 mol/L.The relative standard deviations£¨RSDs£© of eight measurements were 4.6% for 1.0¡Á10-5 mol/L bisphenol A.This method was applied in the determination of dissoluted bisphenol A in plastics with recoveries of 99%-107%.