| A simple and novel electrochemical method was presented for the detection of bisphenol A(BPA) using spherical silica and gold nanoparticles composite film modified glass carbon electrode(SiO2/Au/GCE).The morphology and structure of SiO2 and SiO2/Au were characterized by scanning electron microscopy(SEM) and Fourier infrared spectrometry(FT-IR).Electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) were used to investigate the surface electrochemical property of SiO2/Au/GCE.The electrochemical behavior of BPA on SiO2/Au/GCE was studied by CV,chronocoulometry(CC),bulk electrolysis with coulometry,linear sweep voltammetry(LSV) and differential pulse voltammetry(DPV).The experimental parameters such as the thickness of film,accumulation time,pH value and scan rate were optimized,and some kinetic parameters were obtained.The results demonstrated that BPA had a good electrocatalytic activity on SiO2/Au/GCE,and the oxidation peak current at the modified electrode was 3 times as high as that at GCE.The electrooxidation of BPA on SiO2/Au/GCE was adsorption controlled,and was totally an irreversible electrode process accompanied by a two electron and two proton electrode reaction.Under the optimal conditions,the oxidation peak current for BPA was linear in the concentration ranges of 0.01-0.50 μmol/L and 0.50-25 μmol/L with a detection limit(S/N=3) of 1.9×10-8 mol/L.The proposed method was successfully applied in the determination of BPA in disposable glove with recoveries of 98.9%-105.3%.The results were consistent with those obtained by high performance liquid chromatography(HPLC). |