Electrochemical Determination of Dopamine on a Glassy Carbon ElectrodeModified by Using Nanostructure Ruthenium Oxide Hexacyanoferrate/Ruthenium Hexacyanoferrate Thin Film

Abstract

Application of mixed ruthenium oxide hexacyanoferrate/ ruthenium hexacyanoferrate glassy carbon electrode for electrochemical determination of dopamine (DA) is described for the first time. The overlapped voltammetric oxidation potentials of ascorbic acid (AA) and DA are separated and shifted to more facile direction, + 170 and + 320mV versus Ag/AgCl, respectively. Voltammetric response of the electrode toward theDA showed a dynamic calibration curve with two linear parts, from 0.50 to 10.00 mu Mand 25.00 to 550.00 mu M DA, and a detection limit of 0.195 mu M. The sensitivity (0.2917 mu A/mu M) and detection limit (0.195 x 10(-7) mu MDA) of this electrode are 21 times higher and 11.5 times lower than those found in our previous paper. The sensor response of 9.95 mu MDA was not affected by 5.0mM of glucose, 4.5mM of fructose, 0.58mM of sucrose, 0.28mM of cystine, 0.25mM of ascorbic acid, 79.60 mu Mof cysteine, and 49.70 mu Mof uric acid and urea. The fabricated sensor was successfully tested for determination of DA in injection medicine and human blood plasma samples.