Cheng Wenlong, Dong Shaojun, Wang Erkang
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, People's Republic of China.
Anal Chem. 2002 Aug 1;74(15):3599-604. doi: 10.1021/ac025661o.
A novel "bottom-up" approach to highly controllable nanoelectrode ensembles (NEEs) has been developed using colloidal nanoparticle self-assembly techniques. This solution-based strategy allows flexible control over nanoelectrode size, shape, and interspacing of the as-prepared NEEs. Atomic force microscopy (AFM) was proved to be a powerful tool to monitor the NEE topography, which yields parameters that can be used to calculate the fractional nanoelectrode area of the NEEs. AFM, ac impedance, and cyclic voltammetry studies demonstrate that most of nanoelectrodes on the NEEs (at least by 9-min self-assembly) are not diffusionally isolated under conventional ac frequency range and scan rates. As a result, the NEEs behave as "nanoelectrode-patch" assemblies. Besides, the as-prepared NEEs by different self-assembling times show an adjustable sensitivity to heterogeneous electron-transfer kinetics, which may be helpful to sensor applications. Like these NEEs constructed by other techniques, the present NEEs prepared by chemical self-assembly also exhibit the enhancement of electroanalytical detection limit consistent with NEE theory prediction.
利用胶体纳米颗粒自组装技术，已开发出一种用于高度可控纳米电极阵列（NEEs）的新型“自下而上”方法。这种基于溶液的策略能够灵活控制所制备的NEEs的纳米电极尺寸、形状和间距。原子力显微镜（AFM）被证明是监测NEEs形貌的有力工具，它能产生可用于计算NEEs的纳米电极面积分数的参数。AFM、交流阻抗和循环伏安法研究表明，在传统交流频率范围和扫描速率下，NEEs上的大多数纳米电极（至少经过9分钟自组装）并非扩散隔离的。因此，NEEs表现为“纳米电极贴片”组件。此外，通过不同自组装时间制备的NEEs对异质电子转移动力学表现出可调的灵敏度，这可能有助于传感器应用。与通过其他技术构建的这些NEEs一样，通过化学自组装制备的当前NEEs也表现出与NEE理论预测一致的电分析检测限的提高。
