短杆菌素在玻碳电极上的电化学氧化行为的研究

On the Electrochemical Oxidation of Tyrothricine Glassy Carbon Electrodes

本文采用了线性扫描伏安法 (LSV) ,循环伏安法 (CV) ,双电位阶跃计时库仑法 (CC)等多种现代电化学方法并结合紫外可见吸收光谱法 ,研究了短杆菌素 (TYN)在不同的 pH缓冲溶液中 ,于玻碳电极上的电化学氧化行为和反应机理。研究结果表明TYN在玻碳电极上的氧化是一个不可逆过程 ,该不可逆过程中质子转移数与电子转移数相等。TYN本身在玻碳电极上吸附性不强 ,其电化学氧化反应基本上以扩散控制为主 ,而其电极反应产物不具有电化学活性 ,能强烈吸附于玻碳电极表面 。

The electrochemical oxidation of tyrothricine at glassy carbon electrodes has been studied in aqueous solutions over a wide PH range. The mechanism for the oxidation of tyrothricine was studied by several modern electrochemical techniques including linear sweep voltammetry, cyclic voltammetry, square wave voltammetry and chronocoulometry, and combining with UV spectroscopy. Our studies revealed that the electrochemical oxidation of tyrothricine at glassy electrodes was an overall chemically irreversible process involving the same number of electrons and protons transferrng. Tyrothricine itself did not adsorb at glassy carbon electrodes, however, the electrooxidation product with no electrochemical activity can strongly adsorb at the electrodes, which resulted in deactivation of the electrode surface. The response of tyrothricine was found to be the most sensitive at PH2.0 with square wave voltammetry, and the detection limit was 8.3×10\+\{-7\}mol/L.