Abstract A gold electrode was modified with cysteamine by a self-assembly monolayer technique and covalently coupled with 3-mercaptopropionic acid functionalized silver nanoparticles. The free carboxylic acid groups of the 3-mercaptopropionic acid functionalized silver nanoparticles assembled on gold electrode were bonded with the amine groups of biotin or avidin trough amide linkages. The changes in the interfacial properties of gold electrode modified stepwise were examined by cyclic voltammetry and electrochemical impedance spectroscopy using the ferric/ferrous redox system. The electrochemical sensing properties of covalently bonded biotin or avidin on a gold electrode modified with silver nanoparticle were studied by cyclic voltammetry and electrochemical impedance spectroscopy by the varying concentrations of the bio-affinity molecules in the same redox system. The charge transfer resistance was directly proportional to the concentration of analyte while the response was weakly dependent upon the change in the respective peak anodic currents. The sensing mechanism was established to explain the role of the silver nanoparticles.

中文翻译：

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通过银纳米颗粒修饰的金电极上共价键合的生物素-亲和素对进行电化学传感

摘要 通过自组装单层技术用半胱胺修饰金电极，并与3-巯基丙酸功能化银纳米粒子共价偶联。组装在金电极上的 3-巯基丙酸官能化银纳米粒子的游离羧酸基团通过酰胺键与生物素或抗生物素蛋白的胺基团键合。使用三价铁/亚铁氧化还原系统，通过循环伏安法和电化学阻抗谱研究了逐步改性的金电极界面性质的变化。通过循环伏安法和电化学阻抗谱，通过在同一氧化还原系统中不同浓度的生物亲和分子，研究了共价键合的生物素或抗生物素蛋白在银纳米颗粒修饰的金电极上的电化学传感特性。电荷转移电阻与分析物的浓度成正比，而响应弱依赖于各自峰值阳极电流的变化。建立传感机制来解释银纳米粒子的作用。