Analytical Sciences

Direct Voltammetric Specific Recognition of Dopamine Using Al^III-DA Complexes at the Hanging Mercury Drop Electrode

Fuping ZHANG, Min ZHANG, Jiongjia CHENG, Li YANG, Ming JI, and Shuping BI

School of Chemistry & Chemical Engineering, MOE Key Laboratory for Life Science & State Key Laboratory of Coordination Chemistry of China, Nanjing University, Nanjing 210093, China

In this paper, we firstly report the direct voltammetric recognition and determination of dopamine (DA) by using Al^III-DA complexes at the hanging mercury drop electrode (HMDE). A new sensitive cathodic peak of Al^III-DA can be detected at -900 mV (vs. SCE) in 0.1 M NH₄Cl-NH₃·H₂O-0.1 M KCl buffer solution at pH 8.5. This unique -900 mV cathodic peak arises from the specific interaction between Al^III and DA on the HMDE, whereas other substances with similar structures, such as L-dopa, epinephrine (EP), norepinephrine (NE), catechols, caffeic acid (CA), trihydric phenols and tiron, do not yield any new peak on the voltammograms in the potential range from -100 to -1200 mV when Al^III is added. The distinct voltammetric characteristic of the recognition of DA can effectively inhibit the interferences of both ascorbic acid and uric acid in the DA determination by the direct electrochemistry, which is a major difficulty when a solid electrode is used. The proposed method can be anticipated as an effective means for the recognition of DA in the elucidation of the mechanisms of Parkinson's disease (PD) and Alzheimer's disease (AD) in the presence of Al^III.

J-STAGE: View this article in J-STAGE