tailieunhanh - Simultaneous determination of dopamine in the presence of ascorbic acid and uric acid by electrochemically oxidized screen printed carbon electrode

This research reported the simple method to determine of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA). Three – electrode system manufactured by screen printing method was used due to its disposal and low cost. | Vietnam Journal of Science and Technology 55 (5B) (2017) 78-85 SIMULTANEOUS DETERMINATION OF DOPAMINE IN THE PRESENCE OF ASCORBIC ACID AND URIC ACID BY ELECTROCHEMICALLY OXIDIZED SCREEN PRINTED CARBON ELECTRODE Nguyen Xuan Viet1, 2, *, Yuzuru Takamura1 1 School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi City, Ishikawa 923-1292, Japan 2 Faculty of Chemistry, VNU University of Science, Hanoi, 19 Le Thanh Tong, Hanoi, Vietnam * Email: vietnx@ Received: 15 June 2017; Accepted for publication: 5 October 2017 ABSTRACT This research reported the simple method to determine of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA). Three – electrode system manufactured by screen printing method was used due to its disposal and low cost. The screen printed carbon electrode (SPCE) was oxidized by electrochemical technique in acid medium. The capacity of oxidized electrode for selective detection of dopamine was confirmed in a sufficient amount of ascorbic acid and uric acid. The large separated peaks of DA from ascorbic acid and uric acid are observed. The peak separation between UA and DA, DA and AA was 110 mV and 160 mV, respectively. The bare SPCE cannot determine simultaneously AA and DA due to the overlap peaks of AA and DA around V vs AgCl/Ag. This sensor also exhibited good sensitivity to DA with limit of detection 100 nM in phosphate buffer solution. Keywords: dopamine, electrochemical sensor, electrochemical oxidization, SPCE. 1. INTRODUCTION Dopamine (DA) is a simple organic compound but is an important neurotransmitter substance. DA plays a significant role in the function of the central mammalian brain [1], where the highest DA concentration is approximately 50 nmol/g in a region of the brain known as the “caudate nucleus” (approximately 50 M if the caudate nucleus were considered as a homogeneous phase) [2]. And the very low concentration of DA in the .