RUI: Super-resolution plasmon-enhanced imaging and spectroscopy with patterned metallic surfaces and dynamic illumination

化学部的化学测量和成像计划正在支持内森·林德奎斯特博士和他在贝瑟尔大学的本科研究人员开发使用金属纳米表面的高分辨率成像和光谱学的新方法。衍射限制光学显微镜无法实现在纳米尺度成像、传感和光谱学中的许多要求苛刻的应用所必需的光场控制。为了解决这个问题，等离子体激元领域旨在通过利用金属纳米结构中的等离子体激元来操纵比称为“热点”的光学波长小得多的维度内的光。然后，热点能够通过等离子体增强光谱提供化学信息。利用这些特性，Lindquist博士和他的学生正在开发亚衍射限制的化学成像基底。为了解决与扫描和成像目的的聚焦热点的精确定位相关的挑战，Lindquist博士的团队正在使用空间光调制器和计算机控制的全息激光照明。传统显微镜方法的分辨率为200 nm，这太大了，无法观察许多细胞成分和许多材料的结构细节。该项目使用了一种非常不同的策略来生成显微镜图像：非常小的金属结构，可以将收集的光限制在非常小的尺寸并提高图像质量。 在这项研究中探索的精确纳米制造和纳米表征技术也将产生广泛的科学影响，因为纳米尺度的金属具有许多宏观尺度金属所没有的独特性质。除此之外，这项研究是在一个主要的本科院校进行的，为未来的科学和工程职业培训有动力的学生。学生的工作将把跨学科的研究活动纳入他们的本科教育，为他们提供最先进的设备和实验技术的经验，并激发课程项目，研究活动和夏季研究机会。

The Chemical Measurement and Imaging program of the Division of Chemistry is supporting Dr. Nathan Lindquist and his undergraduate researchers at Bethel University to develop new methods for high-resolution imaging and spectroscopy using metallic nano-surfaces. Diffraction-limited light microscopy cannot achieve the control of optical fields necessary for many demanding applications in nano-scale imaging, sensing, and spectroscopy. To address this issue, the field of plasmonics aims to manipulate light within dimensions much smaller than the optical wavelength called "hotspots" by exploiting plasmons in metallic nanostructures. The hotspots are then able to provide chemical information via plasmon-enhanced spectroscopy. Using these properties, Dr. Lindquist and his students are developing sub-diffraction-limited chemical imaging substrates. To address challenges associated with the precise positioning of focused hotspots for scanning and imaging purposes, Dr. Lindquist's team is using a spatial light modulator and computer-controlled holographic laser illumination.The resolution of conventional microscopic methods is on the order of 200 nm, which is too large to observe many cellular components and the structural details of many materials. This project uses a very different strategy to generate microscope images: very small metal structures that can restrict the light collected to very small dimensions and improve image quality. The precise nano-fabrication and nano-characterization techniques explored in this research also will have broad scientific impact because nano-scale metals have many unique properties that macro-scale metals do not. Beyond this, the research is being performed at a primarily undergraduate institution, training motivated students for future careers in science and engineering. The student's work will incorporate cross-disciplinary research activities into their undergraduate education, give them experience with state-of-the-art equipment and experimental techniques, and inspire course projects, research activities, and summer research opportunities.