Hajian Reza, Yusof Nor Azah, Faragi Tayebe, Shams Nafiseh
Institute of Advanced Technology, University Putra Malaysia, Serdang, Selangor, Malaysia.
Institute of Advanced Technology, University Putra Malaysia, Serdang, Selangor, Malaysia; Department of Chemistry, Faculty of Science, University Putra Malaysia, Serdang, Selangor, Malaysia.
PLoS One. 2014 May 8;9(5):e96686. doi: 10.1371/journal.pone.0096686. eCollection 2014.
In this paper, the electrochemical behavior of myricetin on a gold nanoparticle/ethylenediamine/multi-walled carbon-nanotube modified glassy carbon electrode (AuNPs/en/MWCNTs/GCE) has been investigated. Myricetin effectively accumulated on the AuNPs/en/MWCNTs/GCE and caused a pair of irreversible redox peaks at around 0.408 V and 0.191 V (vs. Ag/AgCl) in 0.1 mol L-1 phosphate buffer solution (pH 3.5) for oxidation and reduction reactions respectively. The heights of the redox peaks were significantly higher on AuNPs/en/MWNTs/GCE compare with MWCNTs/GC and there was no peak on bare GC. The electron-transfer reaction for myricetin on the surface of electrochemical sensor was controlled by adsorption. Some parameters including pH, accumulation potential, accumulation time and scan rate have been optimized. Under the optimum conditions, anodic peak current was proportional to myricetin concentration in the dynamic range of 5.0×10-8 to 4.0×10-5 mol L-1 with the detection limit of 1.2×10-8 mol L-1. The proposed method was successfully used for the determination of myricetin content in tea and fruit juices.
本文研究了杨梅素在金纳米粒子/乙二胺/多壁碳纳米管修饰玻碳电极（AuNPs/en/MWCNTs/GCE）上的电化学行为。杨梅素能有效地在AuNPs/en/MWCNTs/GCE上富集，并在0.1 mol L-1磷酸盐缓冲溶液（pH 3.5）中分别于约0.408 V和0.191 V（vs. Ag/AgCl）处产生一对不可逆的氧化还原峰，分别对应氧化反应和还原反应。与MWCNTs/GC相比，AuNPs/en/MWNTs/GCE上氧化还原峰的高度显著更高，而裸玻碳电极上没有峰。杨梅素在电化学传感器表面的电子转移反应受吸附控制。对pH、富集电位、富集时间和扫描速率等一些参数进行了优化。在最佳条件下，阳极峰电流与杨梅素浓度在5.0×10-8至4.0×10-5 mol L-1的动态范围内成正比，检测限为1.2×10-8 mol L-1。该方法成功用于茶叶和果汁中杨梅素含量的测定。
