NER: Nanowire Based Plasmonic Bioprobes/sensors

本研究的目的是探索利用半导体技术作为进一步增强表面增强拉曼(SER)光谱的可能机制，以开发基于半导体的纳米线生物传感器。本研究以实验和理论两种相辅相成的方式进行。设想了两种设计：传感器由(I)平面衬底上的沟槽中的纳米线和(Ii)微吸管中的纳米线组成。我们将用生物素对这些导线进行功能化处理，并研究偏置、频率、非线性物理和导线密度对信号增强的影响。理论上，我们将使用全波电磁求解器来研究局域化，该求解器与量子力学方法相结合来表征纳米线中的漂移扩散。这个项目的智力优势在于发展了对半导体纳米结构中光的宽带局域化的基本理解，并可以在纳米光子学等领域产生重大影响。使用表面等离子体理解光的局部化产生的更广泛的影响可能导致：(1)可以探测到单个(少数)分子的超灵敏空腔；(2)使用导致超高速处理器的光子来模拟电子行为的能力；(3)导致超紧凑集成光子系统的等离子体波导管。这项拟议研究的一个直接结果是开发了廉价、高选择性、具有快速反馈的生物传感器。我们预计这将对生物安全应用和食源性疾病的农业检测产生重大影响。这些都是农业安全部门公认的脆弱性。这个项目将对不同学科的学生进行培训。

The objective of this research is to investigate the use of semiconductor based technology as a possible mechanism for further enhancement of surface enhanced Raman (SER) spectroscopy toward the development of semiconductor based nanowire biosensors. The approach of this research is done in two complementary ways --experimental and theoretical. Two designs are envisioned; sensors made of (i) nanowires across a trough on a flat substrate, and (ii) nanowires in micropipettes. We shall functionalize these wires with biotin and study the signal enhancement as a function of bias, frequency, nonlinear physics and density of wires. Theoretically, we shall study localization using a fullwave electromagnetic solver that is coupled to quantum mechanical methods to characterize drift diffusion in nanowires.The intellectual merit of this project is in developing a fundamental understanding of broad band localization of light in semiconductor nanostructures and can have a significant impact in nanophotonics, amongst others. The broader impact of understanding localization of light using surface plasmons could result in (1) ultra sensitive cavities that can detect single (few) molecules; (2) ability to mimic electron behavior using photons that lead to ultra high-speed processors; (3) plasmonic waveguides that lead to ultra-compact integrated photonic systems. A direct consequence of the proposed research is the development of inexpensive, highly selective biosensors with rapid feedback. We expect this to have a significant impact in biosecurity applications and in agricultural testing for food borne illnesses. These are stated vulnerabilities of the agro-security sector. This project will train students across disparate disciplines.