Fabrication, design, and analytical applications of nanostructured plasmonic crystals

Surface plasmon resonances (SPRs) are coherent oscillations of electron density occurring at the interface of a metal and a dielectric, which generate an evanescent electric field that decays exponentially within ~100-200 nm from the surface of the metal. Because this enhanced electromagnetic field is highly sensitive to local optical property changes, SPRs have been exploited for real-time, fully label-free form of chemical/biological sensing and imaging or for field-enhanced applications of electronics and photovoltaics. Soft nanoimprint lithography provides inexpensive and versatile replication method to generate uniformly ordered and defined nanostructures over large areas. Plasmonic crystals consisting of squared arrays of nanoholes with high fidelity are fabricated using soft nanoimprint lithography, which exhibit the great potential for analytical applications. The work presented in this dissertation focused on the enhancement of analytical sensitivity of a new class of bimetallic plasmonic crystal and the development of plasmonic imaging technique for complex biomolecular system using nanostructured plasmonic crystal platform. Bimetallic plasmonic crystals were demonstrated as a more sensitive substrate for quantitative bulk-refractive-index (Bulk IR) sensing and surface-enhanced Raman spectroscopy (SERS) compared to mono-metallic plasmonic crystals with the same design rule. The best performances for each application of multispectral and SERS-based sensing were obtained by manipulating the composition of thin metal film, their spatial distribution, and the design rules of the plasmonic crystals. Finite-Difference Time-Domain (FDTD) simulations were used to verify the optical behavior of bimetallic plasmonic crystals and to understand the optimized device form factor. A label-free optical imaging technique using plasmonic crystal was developed to quantitatively investigate the morphology and dynamic vital activities of cell. Polyelectrolyte layer-by-layer assemblies with well-defined thicknesses were used to calibrate the reflection contrast response as a function of thickness of biomolecular thin film on plasmonic crystal, which was theoretically verified through FDTD calculations. As a model system, Aplysia California pedal neurons were cultured on plasmonic crystals and quantified in both dry and liquid conditions. The capability of this plasmonic imaging technique that investigates interaction between cell and substrate in real time was verified by cell detachment using trypsin treatment.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Kang, So-Mi

Contributors dc:contributor

• Nuzzo, Ralph G.
• Braun, Paul V.
• Rogers, John A.
• Sottos, Nancy R.

• Surface Plasmon Resonance (SPR)
• plasmonic crystal
• Surface-Enhanced Raman Spectroscopy (SERS)
• Finite-Difference Time-Domain (FDTD) simulation
• Quantitative Surface Plasmon Resonance (SPR) imaging
• biosensor
• bulk refractive-index sensing
• soft nanoimprint lithography

Statement dc:rights

• Copyright 2014 So-Mi Kang

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/72968

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72968