Electronic Theses and Dissertations

Date

2019

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Chemistry

Committee Chair

Xiaohua Huang

Committee Member

Yongmei Wang

Committee Member

Thang Ba Hoang

Committee Member

Tomoko Fujiwara

Abstract

Multifunctional nanomaterials have emerged as unique nanoplatform with excellent physical and physiochemical properties such as their facile surface chemistry, excellent biocompatibility and remarkable optical properties which allow them to be used for early cancer detection, biological separation, medical imaging, disease detection, and disease treatment. However, due to their small sizes, their size distribution, surface chemistry, and their complex morphology, there is a significant challenge in their synthesis and their characterization. Therefore, a thorough understanding of their structure with a detailed physiochemical characterization and their functional properties is highly essential. In this dissertation, we summarize a tremendous progress that has been made in the last few decades in synthesizing and characterizing magnetic-plasmonic core-shell nanoparticles, mainly iron oxide-gold core-shell nanoparticles. We report different approaches for the synthesis of spherical and anisotropic magnetic plasmonic core-shell nanoparticles focusing on iron-oxide gold core-shell nanoparticles. Growth mechanisms are discussed in detail to provide an understanding of the key factors that play a big role in shape and size of nanoparticles. We have developed iron oxide gold core-shell nanoparticles in different shapes (sphere, popcorn and star) with controllable sizes (70 to 250 nm). The nanoparticles were synthesized via a seed-mediated growth method in which newly formed gold atoms were added onto gold-seeded iron oxide octahedrons to form a gold shell. With their strong magnetic properties, these nanoparticles allow faster biological separation and can be used for medical imaging and will have a very important impact in many different fields including cancer detection and therapy. We have also investigated the use of multifunctional nanomaterials in the detection of cancer-derived exosomes and protein profiling. We have developed a portable, highly sensitive, and highly specific assay based on surface-enhanced Raman scattering gold nanorods and antibody-capture platform on a multi-well capture device. This assay is very sensitive with a limit of detection of 2x10^6 exosomes/mL and can analyze more than 80 samples on a single device within two hours. Through proof of concept studies, we identified HER2 and EpCAM to be breast cancer-derived exosome biomarkers which suggest that they can be used as diagnostic tools for breast cancer.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

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