Abstract l -Cysteine ( l -Cys) is an amino acid of high interest in the electrochemical field since it is one of the five electrochemically active amino acids. Due to the S atom on its side chain, this molecule presents the highest amount of possible oxidation states. The rotating ring disk electrode (RRDE) technique is a very useful method for the investigation of complex mechanisms, such as l -Cys oxidation, as it allows the identification of some intermediates. By rotating disk electrode (RDE), it was possible to observe that the adsorption of l -Cys onto Pt electrodes is influenced by mass transport. The chemical reaction was found to be reversible, while the charge transfer irreversible. The RRDE study facilitated the proposal of an electrochemical-chemical-electrochemical mechanism. The ring current was observed to be dependent on the quadratic of the potential applied to the disk electrode combined with the value of the rotation rate in a soft-model algorithm. The product of this chemical step was oxidized in two steps on the ring, with the first one including the generation of an adsorbed intermediate as the rate-limiting step.

中文翻译：

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l -半胱氨酸氧化研究旋转环盘电极：反应中间体的验证

摘要 l -半胱氨酸（ l -Cys）是电化学领域中备受关注的一种氨基酸，因为它是五种具有电化学活性的氨基酸之一。由于其侧链上的 S 原子，该分子呈现出最高数量的可能氧化态。旋转环盘电极 (RRDE) 技术是研究复杂机制（例如 l -Cys 氧化）的一种非常有用的方法，因为它可以识别一些中间体。通过旋转圆盘电极 (RDE)，可以观察到 l -Cys 在 Pt 电极上的吸附受到传质的影响。发现化学反应是可逆的，而电荷转移是不可逆的。RRDE 研究促进了电化学-化学-电化学机制的提出。观察到环电流取决于施加到圆盘电极的电势的二次方以及软模型算法中的旋转速率值。该化学步骤的产物在环上分两步氧化，第一步包括生成吸附中间体作为限速步骤。