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.
