Quantitative Multispectral Biosensing and Imaging Using Plasmonic Crystals

Conventional surface plasmon resonance (SPR) systems use a prism to couple light into a surface plasmon mode at a metal film-dielectric interface. This cumbersome experimental setup is difficult to integrate into a robust, portable, low-cost, and high-resolution imaging-based device for rapid bioanalytical measurements. More recent work with nanostructured metals, such as nanohole arrays in gold films, enable sensing and imaging of surface binding events using simple, normal incident reflection or transmission configurations. These plasmonic structures exhibit multiple resonances that can be leveraged in sensing applications using multispectral analysis protocols. This thesis describes two new types of low-cost plasmonic crystal sensors formed by soft UV nanoimprint lithography that enable quantitative multispectral analysis of surface binding events in spectroscopic and imaging modes. The first plasmonic optic reported is a quasi-3D crystal consisting of a periodic array of nanoscale holes in a thin gold film with a second, physically separate level of isolated gold disks below each nanoscale hole. The second plasmonic optic reported is a full-3D plasmonic crystal that consists of a polymer embossed with a square array of nanowells covered with a conformal thin gold film. These crystals enable quantitative spectroscopy and imaging of surface binding events with submonolayer sensitivities and micrometer spatial resolution, and can be readily integrated into microfluidic channels for the development of compact form factor devices. Full-3D finite difference time domain calculations are used to accurately model the i transmission spectra and the electromagnetic field distributions in and around the metal nanostructures of the crystals, and to provide insight into the physics underlying the complex optical response of these novel plasmonic structures.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Stewart, Matthew E.

Contributors dc:contributor

• Nuzzo, Ralph G.

• Physics, Optics

Language dc:language

eng

Identifier

(MiAaPQ)AAI3337931

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84322