Preparation of 3D Au NPs-poly-L-glutamate/graphene Nanocomposite Modified Electrode for Sensing of Bisphenol A

摘要

In this work, a simple, sensitive and rapid electrochemical sensor for bisphenol A determination based on a 3D Au NPs-poly-L-glutamate/graphene nanocomposite was proposed and the structures of the nanocomposite were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopic (FTIR) and X-ray diffraction (XRD). The electrochemical behaviors of bisphenol A on the nanocomposite GCE were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the potential range of 0.0 ~ 1.0 V, an irreversible oxidation peak appeared on the modified electrode in 0.1 mol L-1 phosphate buffer solution (pH = 6.0). Under the optimum conditions, the anode peak current of bisphenol A increased linearly with the its concentration in the ranges from 0.009 μmol L-1 to 0.1 μmol L-1 and 0.1 μmol L-1 to 1.0 μmol L-1with the detection limit down to 3×10 ?10 mol L-1 (S/N = 3) and the corresponding linear regression equations were Ipa( μA)= ? 0.1129 C ( μmol L-1) + 0.5532 (N = 6, R2 = 0.9057) and Ipa( μA) = ? 0.05970 C ( μmol L-1) + 0.02182 (N = 5, R2 = 0.9950) respectively. The proposed method was successfully used for the determination of bisphenol A content in wastewater and milk samples, and the recoveries were in the range from 98.10% to 104.9%.