Date of Award

Summer 1-1-2020

Degree Type

Thesis

Degree Name

Master of Science In Biomedical Engineering Degree

Department

Chemical And Biomedical Engineering

First Advisor

Ao, Geyou

Second Advisor

Dr. Xue-Long Sun

Third Advisor

Dr. Moo-Yeal Lee

Abstract

This thesis describes a comprehensive study on the complexation of single-wall carbon nanotubes (SWCNTs) with biopolymers via noncovalent and covalent approaches as well as the characterization of the resulting complexes. SWCNTs are unique, onedimensional nanocylinders that are highly attractive for surface modification because all their atoms comprise a surface. Specifically, single-chirality SWCNTs functionalized with biomolecules are excellent candidates for applications in bioimaging, biochemical sensing, and drug delivery. Here, we investigated the complexation affinity of recognition sequences of single-stranded DNA (ssDNA) with SWCNTs. We utilized the optical modulation of ten chirality-pure SWCNTs to study the kinetics of the coating displacement of ssDNA by a strong surfactant. Unique changes were observed for DNASWCNTs hybrids upon surfactant exchange, including distinct reaction time constants ranging from 9 s to 230 s and an increase in photoluminescence ranging from 1.3 to 14.7- fold. Additionally, DNA-wrapped SWCNTs showed unique interaction behavior and stability in cell culture medium. The CTC3TC-(7,6) hybrid exhibited the largest time constant upon surfactant-exchange and was the only hybrid to show an increase in nearinfrared (NIR) fluorescence intensity in serum-containing cell culture medium. Moreover, we explored covalent functionalization of chirality-pure SWCNTs via oxygen doping and oriented immobilization of disaccharide lactose-containing glycopolymers. We observed a strong dependence on oxygen doping on surface-coatings of nanotubes iv when exposing various aqueous dispersions of SWCNTs to short wavelength ultraviolet (UV) light. Our results provide a foundation for future development of applications for chirality-pure SWCNTs in biochemical sensing and imaging advancement. Successful completion of the covalent functionalization of SWCNTs with lactose-containing glycopolymers will lead to the creation of engineered multicolor, fluorescent probes with precise optical and carbohydrate functionalities. These fluorescent probes will serve as a novel nanomaterial tool to enable better understanding of the carbohydrate-protein interactions in biology.

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