摘要
采用电化学方法先在玻碳电极（GCE）表面共价键合一末端带有巯基的2-氨基乙硫醇（AET）单层,通过硫-金相互作用将金纳米颗粒（GNP）固载在玻碳电极表面,制备了GNP修饰的GNP-AET/GCE电极。采用X射线光电子能谱和循环伏安法对固载纳米金的玻碳电极的结构和性能进行表征。研究发现：GNP-AET/GCE电极不仅对抗坏血酸具有良好的催化性能,使其氧化过电位由玻碳电极上的0.53 V负移到0.33 V,氧化峰电流明显增加,而且能将多巴胺和抗坏血酸在玻碳电极上重叠的氧化波分成两个独立的氧化峰,峰间电位差为0.29 V,提出了用差分脉冲伏安法在多巴胺共存在测定抗坏血酸的选择性方法。峰电流与抗坏血酸浓度在8.5×10^-6-1.0×10^-4mol·L^-1之间呈线性关系,其检出限为4.7×10^-6mol·L^-1。
Gold nanoparticle （GNP） modified glassy carbon electrode （GCE） was prepared first by covalent-linking, through electrochemical method, a rnonolayer of 2-aminoethanethiol （AET） on the surface of GCE, and then through intereaction of gold with the mereapto group at the terminal of AET molecule, to immobilize GNP on the surface of the GCE. This modified electrode was named abbreviately as GNP-AET/GCE. The structure and property of the GNP-AET/GCE were characterized by X-my photoelectron spectroscopy and cyclic voltarnrnetry. It was found that GNP-AET/GCE showed not only effective catalytic property to ascorbic acid in making a negative shift of its oxidation potential from 0. 53 V （at bare GCE） to 0. 33 V and a remarkable increase in oxidation peak current, but also a clear separation of the originally overlapped oxidation waves of ascorbic acid and dopamine at the bare GCE into 2 separate oxidation peaks, between which the potential difference attained to a value of 0. 29 V. Based on these findings, a selective method for detemaination of ascorbic acid in the presence of dopamine by differential pulse voltammetry was proposed. Linear relationship between values of peak current and concentration of ascorbic acid was obtained in the range of 8. 5 × 10^-6 -1.0 × 10^-4 mol · L^-1, with its detection limit of 4. 7×10^- 6mol · L^-1.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2008年第4期299-303,315,共6页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
上海市教育委员会资助项目(No.05DZ16)
关键词
玻碳电极
2-氨基乙硫醇
金纳米颗粒
多巴胺
抗坏血酸
Glassy carbon electrode
2-Aminoethanethiol
Gold nanoparticle
Dopamine
Ascorbic acid
