Electrochemical Detection of Sugar-related Compounds Using Boron-doped Diamond Electrodes
Electrochemical Detection of Sugar-related Compounds Using Boron-doped Diamond Electrodes
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DOI：
10.2116/analsci.28.127
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发表时间：
2012-02-01
影响因子：
1.6
通讯作者：
Uchikura, Kazuo
中科院分区：
文献类型：
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作者：
Hayashi, Tomohisa;Sakurada, Ikuo;Uchikura, Kazuo
采用硼掺杂金刚石（BDD）电极作为流动注射分析（FIA）检测器，对糖相关化合物进行电化学检测。糖相关化合物在高施加电位下氧化，因此BDD电极适用于电化学测量。优化了具有BDD检测器的FIA系统的条件，并且对于糖相关化合物实现了以下检测限：单糖，25 - 100 pmol;糖醇，10 pmol;和寡糖，10 pmol。单糖D-葡萄糖（Glu）的检测限为105 pmol（S/N = 3）。方法的线性范围为50 nmol，相对标准偏差为0.65%（20 nmol，n = 6）。在进样器和检测器之间的系统中添加了高效液相色谱（HPLC）柱，并实现了皮摩尔水平的检测限，这与HPLC系统和FIA系统相同。采用循环伏安法和BDD检测器研究了谷氨酸的电化学氧化反应。该反应被证明是不可逆的，并且根据以下两步机理进行：（1）向电极施加高电势（2.00V vs. Ag/AgCl）导致水在电极表面上电解，同时在表面上产生羟基自由基，和（2）羟基自由基间接氧化Glu。因此，可以通过与羟基自由基反应引起的氧化电流的增加来检测Glu。
Electrochemical detection of sugar-related compounds was conducted using a boron-doped diamond (BDD) electrode as a detector for flow-injection analysis (FIA). Sugar-related compounds oxidize at high applied potentials, for which the BDD electrode is suitable for electrochemical measurements. Conditions for an FIA system with a BDD detector were optimized, and the following detection limits were achieved for sugar-related compounds: monosaccharides, 25 - 100 pmol; sugar alcohols, 10 pmol; and oligosaccharides, 10 pmol. The detection limit for monosaccharide D-glucose (Glu) was 105 pmol (S/N = 3). A linear range was acquired from the detection limit to 50 nmol, and the relative standard deviation was 0.65% (20 nmol, n = 6). A high-performance liquid chromatography (HPLC) column was added to the system between the sample injector and the detector and detection limits to the picomole level were achieved, which is the same for the HPLC system and the FIA system. The electrochemical oxidation reaction of Glu was examined using cyclic voltammetry with the BDD detector. The reaction proved to be irreversible, and proceeded according to the following two-step mechanism: (1) application of a high potential (2.00 V vs. Ag/AgCl) to the electrode causes water to electrolyze on the electrode surface with the simultaneous generation of a hydroxyl radical on the surface, and (2) the hydroxyl radical indirectly oxidizes Glu. Thus, Glu can be detected by an increase in the oxidation current caused by reactions with hydroxy radicals.