Application of graphite screen printed electrode modified with dysprosium tungstate nanoparticles in voltammetric determination of epinephrine in the presence of acetylcholine

The current work focuses on the development of a sensitive and selective electrochemical device based on a graphite screen printed electrode modified with Dy-2(WO4)(3) nanoparticles (DWO/SPE) for the analysis of epinephrine in samples also containing acetylcholine. The study proves that the sensor has excellent electron-mediating behavior in the oxidation of epinephrine in a 0.1 mol/L phosphate buffer solution (PBS) (pH 7.0). The application of the DWO/SPE in differential pulse voltammetry (DPV) is found to lead to distinct response for the oxidation of epinephrine and acetylcholine, with the potentials of the epinephrine and acetylcholine peaks (Delta E-p) to be 550 mV apart. The detection limits of the method for epinephrine and acetylcholine are 0.5 and 0.7 mu mol/L (S/N = 3) and the responses are found to be linear in the concentration ranges of 1.0-900.0 mu mol/L and 1.0-1200.0 mu mol/L in a PBS buffer (pH = 7.0) respectively. The modified electrode was used for the detection of epinephrine and acetylcholine in real samples and found to produce satisfactory results. These results can be a proof that Dy-2(WO4)(3) nanoparticles can find promising applications in electrochemical sensors to be used for the analysis of (bio) chemical species. (C) 2018 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.