Boland Susan, Barrière Frédéric, Leech Dónal
School of Chemistry, National University of Ireland, Galway, Ireland.
Langmuir. 2008 Jun 17;24(12):6351-8. doi: 10.1021/la7031972. Epub 2008 May 13.
The production of stable redox-active layers on electrode surfaces can lead to improvements in electronic device design. Enhanced stability can be achieved by pretreatment of electrode surfaces to provide surface chemical functional groups for covalent tethering of redox complexes. Herein, we describe pretreatment of glassy carbon electrodes to provide surface carboxylic acid groups by electro-reduction of an in situ-generated aryl diazonium salt from 3-(4-aminophenyl)propionic acid. This surface layer is characterized by attenuated total reflection infrared spectroscopy, atomic force microscopy, and electrochemical blocking studies. The surface carboxylic acid generated is then used to tether an osmium complex, [Os(2,2'-bipyridyl)2(4-aminomethylpyridine)Cl]PF6, to provide a covalently bound redox-active monolayer, E(0) ' of 0.29 V (vs Ag/AgCl in phosphate buffer, pH 7.4), on the pretreated glassy carbon electrode. The layer proves stable to pH, temperature, and storage conditions, retaining electroactivity for at least 6 months.
在电极表面制备稳定的氧化还原活性层可改善电子器件设计。通过对电极表面进行预处理以提供用于氧化还原复合物共价连接的表面化学官能团，可实现稳定性的增强。在此，我们描述了对玻碳电极进行预处理的方法，即通过电还原原位生成的来自3-(4-氨基苯基)丙酸的芳基重氮盐来提供表面羧酸基团。该表面层通过衰减全反射红外光谱、原子力显微镜和电化学阻断研究进行表征。然后，利用生成的表面羧酸将锇配合物[Os(2,2'-联吡啶)2(4-氨基甲基吡啶)Cl]PF6连接起来，在预处理的玻碳电极上提供一个共价结合的氧化还原活性单层，其标准电极电位E(0)'为0.29 V（相对于pH 7.4的磷酸盐缓冲液中的Ag/AgCl）。该层在pH、温度和储存条件下均表现出稳定性，至少6个月内保持电活性。
