Electrochimica Acta, Vol.75, 360-365, 2012
A novel sensor based on LaPO4 nanowires modified electrode for sensitive simultaneous determination of dopamine and uric acid
LaPO4 nanowires were synthesized by a simple hydrothermal method and characterized using transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). A novel electrochemical sensor has been fabricated by use of a carbon paste electrode (CPE) coated with the prepared LaPO4 nanowires. Electrochemical characterization of the sensor was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The nanowires-LaPO4 showed excellent electrocatalytic activity toward the oxidation of dopamine (DA) and uric acid (UA) simultaneously. Moreover, the sensor exhibits good selectivity toward simultaneous determination of DA and UA. By using DPV method, low detection limits of 1.3 x 10(-7) mol L-1 and 9.0 x 10(-7) mol L-1 for DA and UA were obtained, with the linear calibration curves over the concentration range 4.00 x 10(-7) - 1.14 x 10(-5) mol L-1 and 2.70 x 10(-6) - 2.48 x 10(-5) mol L-1, respectively. In addition, the sensor was successfully applied for the determination of analytes in injection samples using the standard adding method with satisfactory results. (C) 2012 Elsevier Ltd. All rights reserved.