Design and Development of Nanoconjugates for Nanotechnology

<p>Nanotechnology builds devices from the bottom up with atomic accuracy. Among the basic nano-components to fabricate such devices, semiconductor nanoparticle quantum dots (QDs), metal nanocrystals, proteins, and nucleic acids have attracted most interests due to their potential in optical, biomedical, and electronic areas. The major objective of this research was to prepare nano-components in order to fabricate functional nano-scale devices. This research consisted of three projects. In the first two projects, we incorporated two desirable characteristics of QDs, which are their abilities to serve as donors in fluorescence energy transfer (FRET) and surface energy transfer (SET) as well as to do multiplexing, to engineer QD-based nanoconjugates for optical and biomedical applications. Immobilizing luminescent semiconductor CdSe/ZnS QDs to a solid platform for QD-based biosensors offers advantages over traditional solution-based assays. In the first project, we designed highly sensitive CdSe/ZnS QD SET-based probes using gold nanoparticles (AuNPs) as FRET acceptors on polystyrene (PS) microsphere surfaces. The emission of PS-QD was significantly quenched and restored when the AuNPs were attached to and then removed from the surface. The probes were sensitive enough to analyze signals from a single bead and for use in optical applications. The new PS-QD-AuNP SET platform opens possibilities to carry out both SET and FRET assays in microparticle-based platforms and in microarrays. In the second project, we applied the QD-encoded microspheres in FRET-based analysis for bio-applications. QDs and Alexa Fluor 660 (A660) fluorophores are used as donors and acceptors respectively via a hairpin single stranded DNA. FRET between QD and A660 on the surface of polystyrene microspheres resulted in quenching of QD luminescence and increased A660 emission. QD emission on polystyrene x microspheres was restored when the targeted complementary DNA hybridized the hairpin strand and displaced A660 away from QDs. The third project involved fabrication of different nanoconjugates via self-assembly of template-based metal nanowires and metal nanoparticles using oligonucleotides as linkers. These nanoconjugates can serve as building blocks in nano-electronic circuits. The template method restricted the oligonucleotides attachment to the tip of the nanowires. Nanowires tagged with hybridizable DNA could connect to complementary DNA-modified metal crystals in a position-specific manner.</p>

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation-Restricted

Discipline thesis:degree_discipline

Chemistry

Year

2011

Author dc:creator

• Quach, Ashley Dung

Contributors dc:contributor

• Rosenzweig, Zeev; Tarr, Matthew A.
• Cole, Richard B.
• Cai, Yang

• Nanotechnology
• Nanoconjugates
• Quantum Dots
• Metal Nanocrystals
• Metal Nanowires
• Peptides
• Oligonucleotides
• DNA
• Surface Energy Transfer (SET)
• Fluorescence Resonance Energy Transfer (FRET)
• Multiplexing
• Microspheres
• Probes
• Biosensors
• Self-Assembly

Repository record dc:identifier

https://scholarworks.uno.edu/td/130

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-1129