一种修饰微电极的制备及其在维生素C测定中的应用

A new preparation method of modified microelectrodes and their applications in vitamin C measurement

研究了一种新颖的微电极的制备方法。借此可以通过改变电极中的填充物质的种类与组成,简便地获得各种特性的修饰微电极。采用循环伏安法,以维生素C(Vc)为模型化合物,在不同pH条件下评价了所制备的4种微电极的性能。实验发现,相比未修饰玻碳电极,Vc在各种微电极上的峰电位都有明显下降,从而降低了Vc氧化产物因扩散慢而对电极的污染。同时,制备的4种微电极的峰电流密度相比未修饰玻碳电极,均有3至45倍的增加,并用不同扫描速率探索了Vc在不同掺杂微电极表面的电化学行为的差异。

In this paper, a new method to prepare modified microelectrodes was developed. By utilizing such method, different modified microelectrodes can be prepared conveniently, only by changing the conductive packing materials. In this paper four kinds of microelectrodes prepared were evaluated by cyclic voltammetry, using Vitamin C （Vc） as a compound model. Results showed that over-potential of Vc decreased significantly compared to that at the bare glassy carbon electrode. The decrease of over-potential indicated that the electrode pollution caused by slow diffusion of oxidative production of Vc could be alleviated. Compared to the bare glassy carbon electrode, the peak current densities of all microelectrodes increase 3 to 45 folds. By varying the scan rate and pH of buffer solutions, the electrochemical behaviors of Vc on the surfaces of such four microelectrodes were explored.