Electrocatalytic Amplification of Nanoparticle Collisions at Electrodes Modified with Polyelectrolyte Multi layer Films
Electrocatalytic Amplification of Nanoparticle Collisions at Electrodes Modified with Polyelectrolyte Multi layer Films
复制标题
DOI：
10.1021/la5043124
复制
发表时间：
2015-01-20
期刊：
影响因子：
3.9
通讯作者：
Crooks, Richard M.
中科院分区：
文献类型：
--
作者：
Castaneda, Alma D.;Alligrant, Timothy M.;Crooks, Richard M.
我们报道了直径为 57 nm 的 Pt 纳米粒子 (Pt NP) 和直径为 12.5 μm 的 Au 超微电极之间的单独碰撞的电化学催化放大，这些电极采用通过逐层沉积方法制备的钝化静电组装聚电解质多层 (PEM) 薄膜进行修饰。报告了两个重要发现。首先，尽管绝缘 PEM 薄膜的厚度高达 5 nm，但电子仍能够从 Pt NP 隧道到电极，从而在 PEM 薄膜-溶液界面处产生电催化 N2H4 氧化。这些单粒子测量结果与先前的报告一致，表明钝化 PEM 薄膜的电化学活性可以通过金属纳米粒子的吸附来重新激活。其次，可以通过操纵 PEM 薄膜外表面上存在的净静电荷来控制碰撞频率。这些结果表明化学可用于控制电催化放大，为未来的传感应用奠定了基础。
We report electrochemical catalytic amplification of individual collisions between similar to 57 nm diameter Pt nanoparticles (Pt NPs) and 12.5 mu m diameter Au ultramicroelectrodes modified with passivating, electrostatically assembled polyelectrolyte multilayer (PEM) films prepared by the layer-by-layer deposition method. Two key findings are reported. First, despite the thicknesses of the insulating PEM films, which range up to 5 nm, electrons are able to tunnel from the Pt NPs to the electrode resulting in electrocatalytic N2H4 oxidation at the PEM film-solution interface. These single-particle measurements are in accord with prior reports showing that the electrochemical activity of passive PEM films can be reactivated by adsorption of metallic NPs. Second, it is possible to control the frequency of the collisions by manipulating the net electrostatic charge present on the outer surface of the PEM thin film. These results, which demonstrate that chemistry can be used to control electrocatalytic amplification, set the stage for future sensing applications.