A modified disposable electrode formed by immobilization of glucose dehydrogenase (DHG) onto pyrocatechol violet (Pcv)-modified graphite pencil electrode (GPE) was proposed for the flow injection (FI) amperometric glucose biosensor. Cyclic voltammetric experiments show that Pcv illustrates a good electrocatalytic effect towards the oxidation of enzymatically produced NADH. Although electrocatalytic oxidation of enzymatically generated NADH at the DHG/Poly-Pcv/GPE was successfully performed at + 250 mV in FIA system, some molecules such as ascorbic acid (AA), dopamine (DA) and uric acid (UA) give a significant positive interference due to their oxidation at this working potential. To overcome these interferences, an injector filled with a pre-oxidant, sodium bismuthate (NaBiO₃), was used in the FI amperometric glucose biosensor at the DHG/Poly-Pcv/GPE. Results showed that the interferences of these molecules were significantly minimized, because they were oxidized by NaBiO₃ in the injector before reaching the electrode surface in the flow cell. The constructed biosensor showed that a linear calibration curve was obtained in the range between 5.0 µM and 500 µM glucose with a detection limit of 1.2 µM. This proposed glucose biosensor including elimination of interferences of some oxidizable species was successfully applied to the real and artificial samples.

中文翻译：

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邻苯二酚紫/葡萄糖脱氢酶修饰的石墨笔电极的干扰最小化-FIA葡萄糖生物传感器的开发

提出了一种通过将葡萄糖脱氢酶（DHG）固定在邻苯二酚紫（Pcv）修饰的石墨笔电极（GPE）上而形成的修饰一次性电极，用于流动注射（FI）安培型葡萄糖生物传感器。循环伏安实验表明，Pcv对酶促生成的NADH的氧化具有良好的电催化作用。尽管DIA / Poly-Pcv / GPE在DIA / Poly-Pcv / GPE上以酶催化生成的NADH在250 mV的电压下成功进行了电催化氧化，但某些分子（例如抗坏血酸（AA），多巴胺（DA）和尿酸（UA））的含量却很高在此工作电位下由于其氧化而产生正干扰。为了克服这些干扰，需要在注射器中填充预氧化剂铋钠（NaBiO ₃）用于DHG / Poly-Pcv / GPE的FI安培葡萄糖生物传感器。结果表明，由于这些分子在到达流通池中的电极表面之前已被进样器中的NaBiO ₃氧化，因此其干扰得以显着降低。所构建的生物传感器显示出在5.0 µM至500 µM葡萄糖之间的线性校准曲线，检测限为1.2 µM。该提议的包括消除某些可氧化物种干扰的葡萄糖生物传感器已成功应用于实际和人工样品。