Faculty of Chemistry and Material Science, Hubei University, Wuhan 430062, People's Republic of China.
Talanta. 2002 Jun 10;57(4):687-92. doi: 10.1016/s0039-9140(02)00072-3.
The electrochemical behaviors of epinephrine (EP) at the l-cysteine self-assembled monolayers modified gold electrode have been studied. The modified electrode shows an excellent electrocatalytic activity for the oxidation of EP and accelerates electron transfer rate. The diffusion coefficient (D) is 1.48x10(-7) cm(2) s(-1). FTIR has shown that cysteine can bind onto the gold surface through the strong sulfur-gold interaction. The electrocatalytic mechanism to EP has been studied. The catalytic current of EP nu s its concentration has a good linear relation in the range of 1.0x10(-7)-2.0x10(-6) mol l(-1), with the correlation coefficient of 0.9989 by differential pulse voltametric (DPV) response. Detection limit is down to 1.0x10(-8) mol l(-1). At a high EP concentration, the relationship between the catalytic current and its concentration exhibits a Michaelis-Menten kinetic mechanism for the electrocatalytic process and the constant K(m) is about 0.155 mmol l(-1). The highest catalytic current I(m) is 2.72 muA. The modified electrode can be used for the determination of EP in practical injection. The method is simple, quick, sensitive and accurate.
已研究了肾上腺素（EP）在 L-半胱氨酸自组装单层修饰金电极上的电化学行为。修饰电极对 EP 的氧化表现出极好的电催化活性，并加速了电子转移速率。扩散系数（D）为 1.48x10(-7) cm(2) s(-1)。傅里叶变换红外（FTIR）表明，半胱氨酸可以通过强硫-金相互作用结合到金表面上。研究了 EP 的电催化机制。通过差分脉冲伏安法（DPV）响应，EP 的催化电流与其浓度在 1.0x10(-7)-2.0x10(-6) mol l(-1)范围内呈良好线性关系，相关系数为 0.9989。检测限低至 1.0x10(-8) mol l(-1)。在高 EP 浓度下，催化电流与其浓度之间的关系表现出电催化过程的米氏-门捷列夫动力学机制，常数 K(m)约为 0.155 mmol l(-1)。最大催化电流 I(m)为 2.72 muA。修饰电极可用于实际注射液中 EP 的测定。该方法简单、快速、灵敏、准确。
