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本文提出一种由微型碳纤维工作电极(直径=10μm)、Pt对电极和Ag/AgCl参考电极组成的一氧化氮(NO)探针。该碳纤维电极上覆盖一层Nafion阳离子交换薄膜。以Ag/AsCl电极为参比,采用示差脉冲伏安法(DPV),我们发现NO还原为N_2O电流峰大约在—1.35V。这个结果在其它的文献中也曾提到。在溶液中的NO浓度为2—10μM范围时,DPV输出电流与之呈线性关系。儿茶酚胺对还原信号没有干扰。在正常的生理pH值下,Nafion薄膜能阻止NO_2~-、NO_3~-、氨基酸的干扰。O_2的影响通过采样和从峰电流中扣除背景电流被消除。为了增加灵敏度和缩短反应时间,本研究采用一种积分脉冲安培法(IPA),IPA的电量(△C)与50—350nM的NO有线性关系。碳纤维电极还可做得更小,从而可检测到生物体内皮层空间释放出的NO。
This paper presents a nitric oxide (NO) probe composed of a working electrode of carbon fiber (diameter = 10 μm), Pt counter electrode and Ag / AgCl reference electrode. The carbon fiber electrode covered with a layer of Nafion cation exchange membrane. Taking the Ag / AsCl electrode as a reference and using differential pulse voltammetry (DPV), we found that the reduction of NO to N2O is about -1.35V. This result has also been mentioned in other documents. The DPV output current is linearly related to the concentration of NO in solution in the 2-10 μM range. Catecholamines did not interfere with the reduction signal. Under normal physiological pH, Nafion membrane can prevent the interference of NO2 -, NO3 -, amino acids. The effect of O_2 is eliminated by sampling and subtracting the background current from the peak current. In order to increase the sensitivity and shorten the reaction time, an integrated pulse amperometric method (IPA) was used in this study. The power of IPA (△ C) was linear with NO of 50-350nM. Carbon fiber electrodes can also be made smaller, which can detect the release of NO inside the body’s cortical space.