Rare Earth Oxide Dy2O3-Au Nanocomposite-Based Electrochemical Sensor for Sensitive Determination of Nitrite

The synthesis of rare earth oxide based Dy2O3-AuNPs nanocomposites via solvothermal and in-situ reduction method for the electrochemcial oxidation of nitrite on a glassy carbon electrode (GCE) with high catalytic activity has been reported. The obtained nanocomposites were characterized by transmission electron microscopy (TEM), UV-vis absorption and powder X-ray diffraction (XRD). The electrochemical behavior of the Dy2O3-AuNPs modified GCE was investigated. The effect of pH value on the response current of the sensor was examined. The fabricated enzyme-free sensor achieved a wide linear range of 0.01 similar to 1.0 mmol . L-1 with the detection limit of 3.3 mu mol . L-1. The linear regression equation is Ipa (mu A) = 6.70 + 51.1 C (mmol . L-1) with the square of correlation coefficient R-2 = 0.965. Furthermore, the sensor exhibited the excellent selectivity and reproducibility. When employed for the real sample analytical application, it owned appropriate recovery of nitrite in water samples, indicating the potential application in real sample analysis. (C) 2017 The Electrochemical Society. All rights reserved.