Maeda H
Graduate School of Pharmaceutical Sciences, Osaka University, Japan.
Yakugaku Zasshi. 2000 Feb;120(2):170-82. doi: 10.1248/yakushi1947.120.2_170.
Anodization of a glassy carbon (GC) in a 1-alkanol in a cycled or constant potential mode serves as a useful tool for preparing a chemically modified GC electrode. By this treatment, 1-alkanol molecules are fixed on the GC surface via ether linkage. As the 1-alkanol in the anodic modification, CH3(CH2)nOH (1: n = 0-7), HO(CH2)nOH (2: n = 1-5), and HO(CH2CH2O)nR (3: n = 1-4, R = H; 4: n = 1-3, R = CH3) are utilized. The surface of a GC electrode anodized in the 1-alkanol remarkably reflects the identities of the modifiers. Some of the modified GC electrodes exhibit surface characteristics useful for electroanalytical application as follows: (1) the surface of the GC electrode anodized in 3 or 4 is hydrophilic and resists protein adsorption. An HPLC system equipped with an electrochemical detector employing the GC plate anodized in triethylene glycol as a working electrode has proven to provide a useful analytical method for a protein-containing sample; (2) in the course of anodization of the GC electrode in 2, the diol molecules are first fixed on the surface via ether linkage with one of hydroxyl groups, and the remaining terminal hydroxyl groups in some of the fixed molecules are then oxidized to carboxyl groups. Thus, the GC electrode anodically modified with 2 has carboxyl groups on the surface, which allow dopamine to be voltammetrically discriminated from ascorbic acid in a large excess; (3) when the GC electrode is anodized in triethylene glycol containing HOCH2CH2SO3Na, carboxyl groups are effectively introduced on the surface. On the basis of the formation of an amide bond formation through chemical reaction between the functional groups and amino compounds, electrochemical catalysts such as 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) and catechol are immobilized on the surface of the GC electrode. The obtained electrodes shows stable voltammetric and electrochemically catalytic performance probably because the catalytic molecules are confined on the electrode surfaces via a hydrophilic linker instead of a hydrophobic one.
在循环或恒电位模式下于一元醇中对玻碳（GC）进行阳极氧化，是制备化学修饰玻碳电极的一种有用方法。通过这种处理，一元醇分子通过醚键固定在GC表面。作为阳极修饰中的一元醇，使用了CH3(CH2)nOH（1：n = 0 - 7）、HO(CH2)nOH（2：n = 1 - 5）和HO(CH2CH2O)nR（3：n = 1 - 4，R = H；4：n = 1 - 3，R = CH3）。在一元醇中阳极氧化的GC电极表面显著反映了修饰剂的特性。一些修饰后的GC电极表现出对电分析应用有用的表面特性，如下所述：（1）在3或4中阳极氧化的GC电极表面具有亲水性且能抵抗蛋白质吸附。配备有以在三甘醇中阳极氧化的GC板作为工作电极的电化学检测器的高效液相色谱系统，已被证明可为含蛋白质样品提供一种有用的分析方法；（2）在GC电极于2中进行阳极氧化的过程中，二醇分子首先通过与一个羟基形成醚键固定在表面，然后一些固定分子中剩余的末端羟基被氧化为羧基。因此，用2进行阳极修饰的GC电极表面具有羧基，这使得多巴胺能够在大量过量的抗坏血酸存在下通过伏安法进行区分；（3）当GC电极在含有HOCH2CH2SO3Na的三甘醇中进行阳极氧化时，羧基有效地引入到表面。基于官能团与氨基化合物之间通过化学反应形成酰胺键，电化学催化剂如2,2,6,6 - 四甲基哌啶基 - 1 - 氧基（TEMPO）和儿茶酚被固定在GC电极表面。所获得的电极显示出稳定的伏安和电化学催化性能，这可能是因为催化分子通过亲水性连接基而非疏水性连接基被限制在电极表面。
