Nonlinear optical spectroscopy for studying surface chemistry at complex interfaces and super-resolution optical microscopy

我们使用激光作为主要的分析工具来研究环境条件下的表面化学，例如空气/液体和液体/固体界面。这些复杂界面的分析在技术上是具有挑战性的，因为大多数分析技术不能穿透液体层进入埋藏的液体/固体界面。和频产生（SFG）振动光谱使我们能够获得这些复杂界面的分子水平的信息。我们将使用一种新的方法来进行SFG光谱，并获得新的知识的吸附和取向的分子在界面上。这些信息对于理解与环境，水处理，材料和生物系统相关的许多物理，化学和生物过程非常重要。 此外，我们利用激光的特殊光学特性来构建一种新型的光学显微镜，称为超分辨率显微镜，它能够在衍射极限以下成像20倍。人们认为，自从Ernst Abbe在1873年计算出理论衍射极限分辨率以来，光学显微镜的分辨率永远不会超过光波长的一半（约250 nm）。然而，在过去几年中，由于物理学家、化学家和生物学家的共同努力，情况发生了变化。该提案将提出两种不同的超分辨率显微镜，在UBC建造，分辨率为10 - 50 nm，以研究生物/生化过程，如心肌细胞中的Ca 2+动力学，质膜中的结构域形成和神经元发育。新型显微镜前所未有的空间分辨率完全改变了我们对成像的期望，并将为研究人员提供许多新的可能性。

We use lasers as main analytical tools to study surface chemistry under ambient conditions, such as air/liquid and liquid/solid interfaces. Analysis of these complex interfaces is technically challenging because most analytical techniques cannot penetrate a liquid layer to access the buried liquid/solid interface. Sum frequency generation (SFG) vibrational spectroscopy allows us to obtain molecular-level information about these complex interfaces. We will use a new approach to carry out SFG spectroscopy and obtain new knowledge about the adsorption and orientation of molecules at the interfaces. The information is important for understanding many physical, chemical, and biological processes related to the environment, water treatments, material and biological systems. Additionally, we take advantage of special optical properties of lasers to build a new type of optical microscopes, called super-resolution microscopes, which are capable of imaging 20 times below the diffraction limit. It was believed since Ernst Abbe calculated the theoretical diffraction-limited resolution in 1873 that optical microscopy would never reach resolutions better than half the wavelength of light (~250 nm). However, the situation has changed in the past several years due to the combined efforts of physicists, chemists, and biologists. This proposal will present two different super-resolution microscopes built at UBC with 10 - 50 nm resolution to investigate biological/biochemical processes, such as Ca2+ dynamics in heart muscle cells, domain formation in plasma membranes, and neuron developments. The unprecedented spatial resolution of the new microscopes has totally changed our expectations for imaging and will provide many new possibilities for researchers.