Investigation to develop a nitric oxide-selective electrode

NO选择电极是一种易于应用的实时测量一氧化氮（NO）的工具。工作电极（直径0.2 mm）由镀有三层膜的Pt/Ir合金制成。对电极由碳纤维制成。当使用稳定的NO供体s -亚硝基-n -乙酰-dl-青霉胺时，电极电流呈剂量依赖性增加。电流与计算得到的NO浓度在0.2 nM (S/N=1) ~ 1 muM范围内呈线性关系。电极的响应为1.14(]SY.+- . [)0.09s。温度、pH值和除NO以外的化学物质对电极电流的影响也进行了评估。电极放置在大鼠主动脉环管腔侧，由于加入10<@D1-6@>D1M的乙酰胆碱诱导NO产生，电流为30 pA。电流在50 muM N<@D1G@> d1 -单甲基- l-精氨酸（NO合成酶抑制剂）存在下消除。因此，该NO选择电极适用于生物系统中实时NO测定。NO+2H_2O*NO^-_+4H^++3e^-。施加约0.8 V的正电压以区分来自可能污染物的电流

An NO-selective electrode was developed as an easily applicable tool for a real-time nitric oxide (NO) measurement. The working electrode (0.2 mm diam) was made from Pt/Ir alloy coated with a three-layred membrane. The counterelectrode was made from a carbon fiber. When a stable NO donor, S-nitroso-N-acetyl-dl-penicillamine, was applied, the electrode current increased in a dose-dependent fashion. The current and calculated NO concentration showed a linear relationship in the range from 0.2 nM (S/N=1) to 1 muM of NO.The response of the electrode was 1.14(]SY.+-。[)0.09s. The effects of temperature, pH,and chemicals other than NO on the electrode current were also evaluated. Electrodes which were placed in the luminal side of rat aortic rings exhibited 30 pA of current due to NO generation induced by the addition of 10<@D1-6@>D1M of acetylcholine. The current was eliminated in the presence of 50 muM N<@D1G@>D1-monomethyl-L-arginine, an inhibitor of NO synthase. Thus, this NO-selective electrode is applicable to real-time NO assay in biological systems.NO+2H_2O*NO^-_+4H^++3e^-.A positive voltage of approximately 0.8 V was applied t discriminate against the current from possible contaminant