MRI: Development of a time-resolved, high resolution nonlinear optical microscope for interfacial studies

该奖项由重大研究仪器(MRI)、化学研究仪器(CRIF)和化学测量和成像(CMI)计划支持。坦普尔大学的埃里克·博尔盖特教授和同事戴海龙开发了一种时间分辨率、高分辨率光学显微镜。这种显微镜使用激光来探测活细胞中的蛋白质膜等样品或金纳米颗粒表面等纳米材料。激光与样品的相互作用产生了被研究材料的图像。能够成像具有时间分辨率和分子特异性的界面对于理解广泛的生物、化学和材料系统是重要的。例如，它是研究界面水分子的重要方法。这种新型显微镜提供了记录图像的能力，说明了生物细胞和底物之间的界面上的水结构，这是了解细胞黏附的关键信息。它被用来监测活细胞膜上的分子吸附(例如药物)和运输。研究生参与仪器的开发和测试，接受商业仪器公司寻求的一项重要技能的培训。一旦该仪器可供使用，本科生将在实验室课程中接受使用培训。来自不同大学的多名研究人员正在利用这一资源。这项研究的目的是加强各级研究和教育。显微镜以毫秒的时间间隔记录样品的图像，并以亚微米的空间分辨率产生二阶非线性光学信号。该显微镜使用基于光纤的激光系统，可在可见光和红外范围内提供高重复频率、高脉冲能量的超快激光脉冲，以促进各种材料和分子在表面/界面产生共振增强的二次谐波(SHG)和和频率(SFG)。该显微镜能够成像活细胞膜上具有区域特异性的分子运输。此外，它还允许使用非线性振动显微镜检查非特异性细胞黏附，并观察胶体物体表面的分子相互作用。该仪器还用于利用非线性光学显微镜研究界面上的二维材料，并用于确定活细胞内和外核膜蛋白质的取向和分布。该显微镜还为研究人员探测金纳米颗粒上的表面结合配体，并可视化量子材料中的电子对称破缺提供了服务。它还被用于通过红外成像对软骨组织工程策略进行评估，以及使用时间分辨的高分辨率成像对新型芯片上器官系统中的白细胞-内皮相互作用进行成像。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is supported by the Major Research Instrumentation (MRI), the Chemistry Research Instrumentation (CRIF) and the Chemical Measurement and Imaging (CMI) Programs. Professor Eric Borguet from Temple University and colleague Hai-Lung Dai have developed a time-resolved, high resolution optical microscope. This microscope employs a laser to probe samples such as protein membranes in living cells or nanomaterials such as the surfaces of gold nanoparticles. The interaction of the laser with the sample produces an image of the material under study. Being able to image interfaces with time resolution and molecular specificity is important to the understanding of a wide variety of biological, chemical and materials systems. For example, it is an important approach for examining interfacial water molecules. This new microscope affords the capability to record images illustrating water structure at the interface between a biological cell and a substrate which is information critical for understanding cell adhesion. It is used to monitor molecular adsorption (for example drugs) and transport at membranes of living cells. Graduate students are involved in the development and testing of the instrument, receiving training in an important skill sought by commercial instrument firms. Once the instrument is available for use, undergraduates will receive training in its usage in laboratory courses. Multiple investigators from various universities are utilizing this resource.This research is aimed at enhancing research and education at all levels. The microscope records images of samples at millisecond time intervals and with submicron spatial resolution producing second order nonlinear optical signals. This microscope uses an optical fiber based laser system which provides high repetition rate, high pulse energy, ultrafast laser pulses in a broad wavelength range in the visible, and IR to facilitate resonantly enhanced second harmonic generation (SHG) and sum frequency generation (SFG) from a variety of materials and molecules at surfaces/interfaces. The microscope enables imaging of molecular transport with region-specificity at living cell membranes. In addition, it permits examination of non-specific cell adhesion using nonlinear vibrational microscopy and the observation of molecular interactions at the surfaces of colloidal objects. The instrumentation is also used for the study of two-dimensional materials at interfaces using nonlinear optical microscopy and for determining inner and outer nuclear membrane protein orientation and distribution in live cells. The microscope also serves researchers probing surface-bound ligands on gold nanoparticles and visualizing electronic symmetry breaking in quantum materials. It is also being used for the evaluation of cartilage tissue engineering strategies by IR imaging, and for imaging of leukocyte-endothelial interaction in a novel organ-on-a-chip system using time-resolved, high-resolution imaging.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.