Single molecule and single particle spectroelectrochemistry

单分子和单粒子光谱电化学

• 批准号: RGPIN-2014-05549
• 负责人: Brolo, Alexandre
• 金额: $ 6.12万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=692302
• 关键词: Single; molecule; single; particle; spectroelectrochemistry

Recent advances in optical methods have allowed the development of spectroscopic techniques for single molecule detection. These techniques have been widely used to unveil important mechanistic aspects, mainly from biological systems. For instance, they can provide information about the changes in protein conformation during binding or regarding the transport of individual species across cell membranes. Electrochemical processes are central to several technologies, including energy generation and storage (fuel cell and batteries). Analytical methods that provide a molecular picture of surface processes in electrochemical conditions could then be explored to improve those technologies. However, single molecules techniques have seldom been applied to study electrochemical processes. In the last few years, our research group has been engaged in the development of metallic nanostructures as convenient platforms to investigate single molecular surface processes. The electric potential in those nanostructures can be controlled and surface chemical reactions can be investigated simultaneously by the electrochemical and spectroscopic response of the system (spectroelectrochemistry). The nanometric dimensions of the metallic system allow the confinement of individual molecules for investigation. The goal of this discovery grant will be to use these advances to develop new hybrid chemical methods, with emphasis on their application in single molecule studies. One aspect of the program will be related to single molecule surface-enhanced Raman scattering (SM-SERS) from electrified interfaces, a technique pioneered by our group. Fundamental investigation of the nature and on the quantification of SERS hotspots will be carried out in combination with electrochemical determination of surface concentrations. This type of information will provide the basis for the determination of kinetics and thermodynamic adsorption properties at the SM level. Near field techniques, such as near-field scanning optical microscopy (NSOM) and tip-enhanced Raman scattering (TERS), will also be implemented to investigate electrochemical properties from single nanoparticle fuel cell catalyst (Au, Au-Pt and Au-Pd nanoparticles) immobilized in carbon supports. Individual properties from a variety of clusters will lead to a better understanding of their effect on the average property of the catalyst. A second approach to SM spectroelectrochemistry will involve the application of periodic array of nanoholes (PANH) in gold thin films as nanoelectrodes. Only the volume inside the holes will be electrochemically accessible, so, each individual hole will work as attoliter vials for nanoelectrochemistry experiments. The PANH electrodes will be used to study the electrochemistry dynamics of of single proteins and will became a new platform for single molecule electrochemistry studies.*The research proposed here will then provide fundamental insights into molecular aspects of technological significance to the field of electrocatalysis, particularly for fuel cells. These projects will also culminate in devices for single molecule interrogation that will be translated to biomedical applications for the analysis of a single living cell and in neurochemistry.

光学方法的最新进展允许开发用于单分子检测的光谱技术。这些技术已被广泛用于揭示重要的机械方面，主要来自生物系统。例如，他们可以提供有关结合过程中蛋白质构象变化或单个物种跨细胞膜的转运的信息。电化学工艺对于几种技术（包括能源产生和存储（燃料电池和电池））至关重要。然后可以探索在电化学条件下提供表面过程的分子图的分析方法，以改善这些技术。但是，单分子技术很少应用于研究电化学过程。在过去的几年中，我们的研究小组一直从事金属纳米结构的开发，作为研究单分子表面过程的便捷平台。这些纳米结构中的电势可以受到控制，并且可以通过系统的电化学和光谱反应（SpectroelectroctroChemistry）同时研究表面化学反应。金属系统的纳米尺寸允许将个体分子限制进行研究。这项发现赠款的目的是利用这些进步来开发新的混合化学方法，重点是它们在单分子研究中的应用。该程序的一个方面将与来自电气界面的单分子表面增强拉曼散射（SM-SERS）有关，这是我们组启用的一种技术。对SERS热点的性质和定量的基本研究将与表面浓度的电化学确定结合进行。这种类型的信息将为确定SM水平的动力学和热力学吸附特性提供基础。还将实施近场技术，例如近场扫描光学显微镜（NSOM）和尖端增强的拉曼散射（TERS），以研究来自单纳米粒子燃料电池催化剂（AU，AU-PT，AU-PT和AU-PD纳米颗粒）的电化学性能。来自各种簇的个体性能将使他们更好地了解它们对催化剂平均特性的影响。 SM光谱电化学的第二种方法将涉及将纳米霍尔斯（PANH）定期阵列应用于金薄膜中的纳米电极。只有孔内部的体积才能在电化学上访问，因此，每个孔都可以作为纳米电解化学实验的Attoliter小瓶。 PANH电极将用于研究单蛋白的电化学动力学，并将成为单分子电化学研究的新平台。这些项目还将在单个分子询问的设备中达到高潮，这些设备将转化为生物医学应用，以分析单个活细胞和神经化学。