采用粉末电极技术改善葡萄糖氧化酶电极的抗干扰性能

Improvement of the Anti-interference Characteristics of GOD Electrode by Using the Powder Microelectrode Technique

研究了对电流型ＧＯＤ电极有干扰作用的抗坏血酸、尿酸、Ｌ－半胱氨酸和对－乙酰氨基苯酚在铂、玻碳以及由Ｋｅｔｊｅｎｂｌａｃｋ碳黑填制的粉末微电极上的电化学行为。结果表明：由于这些杂质的电化学活性较高，难以通过选择电极材料及改变工作电位来完全避免它们的干扰作用。然而，抗坏血酸、尿酸及对－乙酰氨基苯酚在粉末微电极上极限电流是由电极端面液相中的扩散传质所控制的，只与电极的表现直径有关而与其真实表面积无关，因而采用粉末微电极技术可明显地提高ＧＯＤ电极的信噪比。

The electrochemical behavior of ascorbic acid(AA),uric acid(UA),L-cystein(L-Cys)and acetaminophen(APAP),i.e.the main interference to the GOD electrode,were studied at the Pt,GC and powder microelectrode. Experimental results indicated that,due to the electrochemical activity of these interference,it is difficult to eliminate their interference effects by manipulation of electrede materials or working potential of the GOD electrode. However,it was found that the limiting curtents at the KB electrode are mainly controlled by mass transfer in liquid phase,so it is only related to the geometer size of the electrode,not its rcal surface area. Therefore,it is possible to enhance significantly the signal/noise ratio of the GOD electrode by using the powder microelectrode technique.