Laboratoire de Chimie, Electrochimie Moléculaire et Chimie Analytique, UMR CNRS 6521, Université de Bretagne Occidentale, 6 Avenue Le Gorgeu, 29238 Brest Cedex 03, France.
Chemistry. 2012 Jan 9;18(2):594-602. doi: 10.1002/chem.201102620. Epub 2011 Dec 9.
A novel and general strategy for the immobilisation of functional objects onto electrodes is described. The concept is based on the addition of two pendant ethynyl groups onto a bis(pyridyl)amine derivative, which acts as a molecular platform. This platform is pre-functionalised with an N(3)-tagged object of interest by Huisgen cycloaddition to one of the ethynyl groups in biphasic conditions. Hence, when complexed by Cu(II) , this molecular-object holder can be immobilised, by a "self-induced electroclick", through the second ethynyl group onto N(3)-alkanethiol self-assembled monolayers on a gold electrode. Two different functional groups, a redox innocent ((CH(2))(3)-Ph) and an electrochemical probe (ferrocene), were immobilised by following this strategy. The in situ electrochemical grafting showed, for both systems, that the kinetics of immobilisation is fast. The voltammetric characterisation of the surface-tagged functionalised copper complexes indicated that a good surface coverage was achieved and that a moderately fast electron-transfer reaction occurs. Remarkably, in the case of the redox-active ferrocenyl-immobilised system, the electrochemical response highlighted the involvement of the copper ion of the platform in the kinetics of the electron transfer to the ferrocene moiety. This platform is a promising candidate for applications in surface addressing in areas as diverse as biology and materials.
介绍了一种将功能客体固定到电极上的新颖通用策略。该策略基于在双吡啶基胺衍生物上添加两个悬挂的乙炔基，将其作为分子平台。该平台通过点击化学预先官能化，通过 Huisgen 环加成将 N(3)标记的感兴趣的客体连接到一个乙炔基上，在两相条件下。因此，当与 Cu(II)配位时，这种分子客体可以通过第二个乙炔基通过“自诱导电点击”固定在金电极上的 N(3)-烷硫醇自组装单层上。通过这种策略，两种不同的功能基团，一个氧化还原惰性的（(CH(2))(3)-Ph）和一个电化学探针（二茂铁）被固定。两种体系的原位电化学接枝表明，固定化动力学很快。表面标记的功能化铜配合物的伏安特性表明实现了良好的表面覆盖度，并且发生了中等快速的电子转移反应。值得注意的是，在具有氧化还原活性的二茂铁固定化体系中，电化学响应突出了平台铜离子在电子向二茂铁部分转移动力学中的作用。该平台是在生物学和材料等多个领域进行表面寻址应用的有前途的候选者。
