Sensitive simultaneous determination of diethylstilbestrol and bisphenol A based on Bi2WO6 nanoplates modified carbon paste electrode.

Bi2WO6 nanoplates were hydrothermally prepared and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The synthesized Bi2WO6 nanoplates were then used to fabricate modified carbon paste electrode (Bi2WO6-CPE) by a simple rubbing method. The result of electrochemical impedance spectroscopy indicated electron transfer resistance of the Bi2WO6-CPE was reduced vastly compared with CPE. In the meantime, cyclic voltammetry experiment demonstrated the Bi2WO6 nanoplates could accelerate the rate of electron transfer for the electrochemical reaction of diethylstilbestrol (DES) and bisphenol A (BPA) on the electrode. Moreover, the as-prepared electrode exhibited good selectivity toward simultaneous determination of DES and BPA with a rather low detection limit. By using differential pulse voltammetry (DPV) method, low detection limits of 15nM (S/N=3) and 20nM (S/N=3) for DES and BPA were obtained, with the linear calibration curves over the concentration range 50-2100nM and 70-1300nM, respectively. In addition, the proposed sensor was applied for the determination of analytes in spiked milk samples extracted from milk powder. [ABSTRACT FROM AUTHOR]