Scanning Electrochemical Microscopy and Ultramicroelectrode Studies Electrochemistry of Single Molecules and Nanoparticles

有了这个奖项，化学测量和成像计划正在支持德克萨斯大学奥斯汀分校的艾伦J.巴德的研究，继续他对一种特殊类型显微镜的开发。该仪器使用一种称为扫描电化学显微镜（SECM）的技术，已在研究人员的实验室中开发多年，并利用一个微小的带电探针悬停在感兴趣的样品上方。当探针在表面上移动时，通过它检测到电信号，并显示样品表面的图像。目前的项目正在研究各种类型的带电尖端或超微电极，与不同类型的表面相互作用，包括非常柔软的表面。例如乳液。这项工作通过直接开发新的科学仪器产生了广泛的影响，这些仪器将应用于从生物学到制造业的各种领域。通过学生研究人员参与该项目，它对下一代科学家的培训产生了进一步的广泛影响。该项目的中心目标是进一步扩展SECM方法，并提高对单个纳米粒子事件的基本理解。这是通过检测和测量不同类型的单个纳米颗粒（NP）和各种电极之间的碰撞来实现的。在这项工作中，电化学研究的新领域包括：（1）改进和先进的理解NP响应;（2）调查新的NP系统，例如软粒子，通过碰撞技术;和（3）隧道层的应用与纳米尺寸的超微电极（UME）具有通过碰撞测量表征大分子的能力。从这项工作中获得的知识在电极上的纳米粒子/表面相互作用的性质，可以揭示在合奏研究中观察不到的微妙现象，如电流密度变化的影响，整个UME表面上，表面上的粒子的运动，微量杂质吸附的失活效应，和单个纳米粒子的动态。随机电化学可能会挑战目前对内球异质电子转移的理解，并为化学能和电能的相互转换提供一条途径。正在进行的实验提供了新的见解和一个新的工具，乳液，胶束和囊泡的研究。

With this award, the Chemical Measurement and Imaging Program is supporting the research of Allen J. Bard of the University of Texas at Austin to continue his development of a special type of microscope. The instrument, which uses a technique known as scanning electrochemical microscopy, or SECM, has been developed in the investigator's lab over a number of years and utilizes a tiny electrified probe hovered just above the sample of interest. As this probe is moved across the surface, electrical signals are detected through it and an image of the sample surface revealed. The current project is investigating various types of electrified tips, or ultramicroelectrodes, interacting with different types of surfaces, including very soft ones. such as emulsions. The work is having a broad impact through the direct development of new scientific instrumentation that will find application in a wide variety of fields from biology to manufacturing. It is having a further broad impact on the training of the next generation of scientists through the participation of student researchers in the project.The central thrust of this project is the development of further extensions of the SECM method and improved fundamental understanding of single nanoparticle events. This is accomplished by the detection and measurement of collisions between different types of single nanoparticles (NPs) and a variety of electrodes. New areas of electrochemical study in this work include: (1) Improved and advanced understanding of NP responses; (2) Investigation of new NP systems, e.g. soft particles, by the collision technique; and (3) Application of tunneling layers with nm-size ultramicroelectrodes (UMEs) with the ability to characterize large molecules by collision measurements. Knowledge gained from this work regarding the nature of nanoparticle/surface interactions at electrodes can reveal subtle phenomena not observable in ensemble studies, such as the effects of current density variations across UME surfaces, motion of particles on surfaces, deactivation effects by trace impurity adsorption, and single nanoparticle dynamics. Stochastic electrochemistry could potentially challenge current understanding of inner-sphere heterogeneous electron transfer, and provide a pathway to advances in inter-conversion of chemical and electrical energy. The experiments being carried out are providing new insights and a novel tool for the study of emulsions, micelles and vesicles.