| Summary: | 碩士 === 國立暨南國際大學 === 應用化學系 === 101 === Dopamine (DA) is an important chemical neurotransmitter in the human body. Electroanalysis of dopamine has been studied in the literatures. A major problem of electrochemical detection of DA is the coexistence of many interfering compounds, such as ascorbic acid (AA) and uric acid (UA). In order to solve this problem, various materials were used to modify the electrode surface, and then improve the analytical performances.
In this study, the sodium 4-aminobenzene sulfonate was used to modify screen-printed carbon electrode by two electrochemical methods. Detecting individual AA, DA and UA in the pH 7.0 buffer solution was achieved by SPCE / 4-ABSA; the oxidation potential of AA, DA and UA were at 0.43, 0.29 and 0.54 V, respectively. Detecting individual AA, DA and UA in the pH 7.0 buffer solution was achieved by SPCE / Ph-SO3; the oxidation potential of AA, DA and UA were at 0.59, 0.37 and 0.53 V, respectively. In the mixed solution, only the peaks of DA and UA can be separated.
In the presence of 100 μM DA, the working range for UA was 10 ~ 100 μM using SPCE / 4-ABSA, and the linear relationship was I＝0.0333*[UA]－0.2992. In a fixed concentration of 100 uM UA, the working range for DA was 1 ~ 200 μM using SPCE / 4-ABSA, and the linear relationship was I = 0.08532 * [DA] +0.7402.
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