以黏粒修飾電極法探討甲基藍之電化學活性

Electrochemical Behavior of Methylene Blue at Clay-modified Electrodes

10.6730/JAAT.201308_14(4).0004

何任于(Ren-Yu Ho)；陳鴻基(Horng-Ji Chen)；曾志明(Jyh-Myng Zen)

黏粒修飾電極 ； 坡縷石 ； 甲基藍 ； Clay-modified electrode ； palygorskite ； Methylene blue

台灣農學會報

14卷4期（2013 / 08 / 01）

354 - 372

繁體中文

甲基藍常被用於細胞或細菌的染色、製藥與工業上的敏光劑，以及以黏土礦物為載體作為藥劑和抗菌劑等用途。以六種黏粒修飾電極對甲基藍進行電化學分析研究結果指出，黏粒修飾電極對甲基藍所偵測到的還原波峯電流量以坡縷石（PFl-1）修飾電極為最大（ipc ＝47.1μA），其次是多鐵蒙特石（SWa-1） 修飾電極（ipc ＝ 45.6μA）；氧化波峯電流量則以SWa-1修飾電極最大（ipa ＝ 46.3μA），且其對甲基藍偵測到的可逆性最大（ipc/ipa ＝ 0.98）。由於坡縷石是一種纖維狀具有隧道式孔洞結構的層狀矽酸鹽礦物，其結晶層邊緣擁有較多的氫氧官能基與可變性電荷，導致在電子傳遞上有較明顯的作用，使得甲基藍通過PFl-1膜層的速率是六種黏粒修飾電極中最大者。對苯二酚的存在使 PFl-1修飾電極對甲基藍偵測之氧化波峯電流量由 18.4μA增大到 47.9μA，顯示由於對苯二酚的電子傳遞促進氧化態甲基藍變成還原態甲基藍。甲基藍通過六種黏粒膜層到電極表面的還原反應主要以擴散機制為主，此可應用於有機污染物通過黏粒層之移動與工業藥劑效能的研究。

Methylene blue has been widely used for dyeing cells or bacteria, as a photosensitizer in pharmacies and industry, and as an antifungal agent with a clay recipient. We studied the electrochemical behavior of methylene blue at six different clay-modified electrodes. The results indicated a high reduction peak current (ipc ＝ 47.1μA) at the palygorskite-modified electrode and ferruginous smectite-modified electrode (ipc ＝ 45.6μA). The highest oxidation peak current (ipa ＝ 46.3μA) and reversibility (ipc/ipa ＝ 0.98) were observed at the ferruginous smectite-modified electrode. Methylene blue shows rapid mobility through palygorskite film with facile electron transfer, presumably due to the fibrous structure and parallel channels or pores coupling with more hydroxyl groups and variable charge in the crystal edges of palygorskite. Hydroquinone can increase the oxidation peak current for methylene blue from 18.4μA to 47.9μA at the palygorskite-modified electrode. The redox peak of methylene blue was diffusioncontrolled at the six clay-modified electrodes studied and can be applied in studying the mobility of organic pollutants through clay films as well as the effect of industrial drugs.