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

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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.