Integration of evanescent wave cavity ringdown spectroscopy with electrochemical methods: A step change in the study of interfacial phenomena

界面是在两个相之间形成的区域，这两个相在一起时不会混合。界面具有独特的物理和化学性质，这些性质在许多科学领域都具有重要的基础和实际意义。例如，固/液和液/液界面可用于催化、合成和传感应用。在生物系统中发现了更复杂的界面，例如构成生物细胞主要组成部分的膜。由于界面区域很薄(纳米级；比人的头发还薄5万倍)，而且它的性质在交叉时会突然变化，所以我们对界面的信息比对均匀的大块相(固体、液体和气体)要少得多。为了理解和探测界面，科学家们需要新的技术来揭示界面的属性。我们的建议是建立一种新的仪器，将分别应用于不同科学领域的两种方法结合起来-扫描电化学显微镜(SECM)，它可以测量溶液中表面发生的反应速度，以及一种称为逝去波腔衰荡光谱(EW-CRDS)的化学表征方法。每种方法都有不同的属性，通过首次将它们结合在一起，我们希望在一系列重要的界面过程中找到新的信息。该方法简单但功能强大：SECM将用于以明确定义的方式在局部尺度上扰动界面或驱动界面过程，而EW-CRDS将以高灵敏度确定扰动导致的化学结果。在这个令人兴奋的新发展中，我们将花费部分项目构建和测试仪器，然后将该方法应用到四个不同的领域，以说明我们期望产生的新信息的广度。我们将研究：(I)模拟生物膜，以发现质子如何沿着膜表面移动，这是活细胞运作的一个关键过程；(Ii)电荷如何在超薄导电聚合物膜中移动，这有可能用于新一代电子设备和传感器；(Iii)金属如何在油和液体之间的区域形成和生长，以更好地了解纳米粒子的形成。我们还将研究是否有可能研究金属电极表面，这将开辟电化学的主要研究领域，最终有可能研究催化剂和传感器表面的作用。

An interface is the region that forms between two phases that do not mix when they are brought together. Interfaces have unique physical and chemical properties, that are of fundamental and practical importance throughout many areas of science. For example, solid/liquid and liquid/liquid interfaces can be used for catalysis, synthesis and sensing applications. More complex interfaces are found in living systems, such as membranes which form a major component of biological cells. Since the interfacial region is so thin (nanometer scale; 50,000 times thinner than a human hair), and its properties change abruptly as it is crossed, we have much less information on interfaces than on uniform bulk phases (solids, liquids and gases). To understand and probe interfaces, scientists require new techniques that can uncover the properties of interfaces. Our proposal is to build a new instrument that combines two approaches that have been applied separately in different areas of science - scanning electrochemical microscopy (SECM) which can measure rates of reactions occuring at surfaces in solution, and a chemical characterisation method called evanescent wave cavity ring down spectroscopy (EW-CRDS). Each method has distinct attributes and by bringing them together for the first time, we expect to find new information on a wide range of important interfacial processes. The approach is simple but powerful: SECM will be used to perturb an interface or drive an interfacial process on a local scale in a well-defined way, while EW-CRDS will determine with high sensitivity what happens chemically as a result of the perturbation. In this exciting new development, we will spend part of the project constructing and testing the instrument and then apply the method to four different areas, to illustrate the breadth of new information that we expect to result. We will study: (i) model biological membranes, to discover how protons move along the membrane surface, which is a key process in the functioning of living cells; (ii) how charges move in ultrathin conducting polymer films, which have the potential to be used in a new generation of electronic devices and sensors; (iii) how metals form and grow in the region between an oil and a liquid, to better understand the formation of nanoparticles. We will also investigate whether it is possible to study metal electrode surfaces, which would open up major areas of electrochemistry for study, with the ultimate possibility of investigating catalyst and sensor surfaces in action.