Electrocatalytic Amplification of Nanoparticle Collisions at Electrodes Modified with Polyelectrolyte Multilayer Films

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• 作者：Alma D. Casta帽eda ; Timothy M. Alligrant ; James A. Loussaert ; Richard M. Crooks
• 刊名：Langmuir
• 出版年：2015
• 出版时间：January 20, 2015
• 年：2015
• 卷：31
• 期：2
• 页码：876-885
• 全文大小：550K
• ISSN：1520-5827

文摘

We report electrochemical catalytic amplification of individual collisions between 鈭?7 nm diameter Pt nanoparticles (Pt NPs) and 12.5 渭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鈥搒olution 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.