Rationally Designed Three-Dimensional Nanostructures for Surface Enhanced Raman Spectroscopy

本研究的目的是综合考虑尺寸、间隙和形状工程、光子设计和三维设计，以实现基于拉曼的实际化学和生物传感应用的最佳表面增强拉曼衬底。设计三维金属纳米结构的光学特性有助于人们对这些纳米结构的等离子体特性有一个基本的了解，并为基于SERS的传感器、金属增强荧光、等离子体传播等应用带来创新的方法。本文将采用时域有限差分方法计算各种金属纳米结构的局部电场分布和光学性质，以了解不同几何因素和耦合的贡献，并设计最佳的传感器衬底。根据理论结果，将采用掠角沉积技术或斜角沉积技术结合其他先进的纳米加工技术来制造和优化传感器基板。更广泛的影响：成功开发一种实用、简单、廉价的技术来制造具有高灵敏度的最佳表面增强拉曼衬底，不仅为用于生物医学诊断、国防和安全的实用拉曼传感器的商业开发奠定了基础，而且在纳米结构制造和工程、基础表面科学和分析光谱学领域也会产生巨大而直接的影响。此外，该项目还将为研究生、本科生和高中生建立严格的材料物理、光子学和纳米技术教育和培训机会。

The objective of this research is to take a comprehensive consideration of size, gap, and shape engineering, photonic design, and three-dimensional design to achieve the best surface enhanced Raman substrates for practical Raman based chemical and biological sensing applications. Engineering the optical properties of three dimensional metallic nanostructures helps one to gain a fundamental understanding of the plasmonic properties of those nanostructures, and bring innovative methods for applications such as SERS based sensors, metal enhanced fluorescence, plasmon propagation, etc.Intellectual Merit: A finite-difference-time-domain method will be used to calculate local electric field distribution and optical properties of various metallic nanostructures in order to understand the contributions of different geometric factors and coupling, and to design optimal sensor substrates. The glancing angle deposition technique or oblique angle deposition technique combining with other sophisticated nanofabrication techniques will be used to fabricate and optimize the sensor substrates according to the theoretical results.Broader Impacts: The successful development of a practical, simple, and inexpensive technique for fabrication of optimal surface enhanced Raman substrates with high sensitivity would not only lay a foundation for commercial development of practical Raman based sensors for biomedical diagnostics, national defense and security, but also have a large and immediate impact in the areas of nanostructure fabrication and engineering, fundamental surface science and analytical spectroscopy. In addition, this project will also establish a rigorous material physics, photonics, and nanotechnology education and training opportunity for graduate, undergraduate, and high school students.