Chen, Yanan
(2013)
Carbon Nanomaterial-Based Biosensing.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Carbon nanomaterials, including carbon nanotubes (CNTs) and graphene, are exciting materials that have been the focus of research in recent years. They have unique physical and chemical properties such as high carrier mobility, high surface-to-volume ratio, and robustness, and are thus considered to be ideal candidates to interact with biological systems. However, the pristine carbon nanomaterials usually suffer from the lack of solubility in aqueous systems. Furthermore, these materials are extremely sensitive to any change in their immediate environment, so it is necessary to decorate these materials with receptor molecules to provide specificity. Therefore the chemical functionalizations of carbon nanomaterials are important before such materials can be incorporated into biosensing devices. There are commonly two approaches of functionalizing carbon nanomaterials, namely covalent and noncovalent methods. Covalent functionalization can provide robust chemical groups onto the surface of carbon nanomaterials. However, this method may disrupt the sp2 structure of carbon nanomaterials and affect the electronic properties of these materials. Noncovalent functionalization can bring the desired functionalization while maintaining the intrinsic electronic properties intact, but leaching of the absorbed materials may be a problem.
In this dissertation, both methods have been used to functionalize carbon nanomaterials towards biosensors. Using noncovalent functionalization scheme, we built two sensing platforms. We used epigallocatechin gallate (EGCG) to noncovalently attach to the surface of single-walled carbon nanotubes (SWNT) and fabricated a resistor-based sensor for hydrogen peroxide. Using porphyrin-based glycoconjugate, we explored the sensitivity of SWNT/glycoconjugate composites towards lectins. Lectins are sugar-binding proteins that exist on the surface of bacteria. Sensing of lectins may lead to the development of bacteria detectors. Furthermore, to explore an optimized system for lectin sensing, we used SWNTs and graphene, as well as different glycoconjugates. It was found out that SWNTs performed better than chemically converted graphene (CCG). Although CCG was not suitable for sensing of lectins using noncovalent functionalization, holey reduced graphene oxide (hRGO), with its interconnected graphene nanoribbon structure and abundant oxygen-containing groups, may be a good platform for biosensing. The functionalization of these groups with antimicrobial peptide can provide specificity to certain bacteria, towards the fabrication of a bacteria detector.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
24 July 2013 |
| Date Type: |
Publication |
| Defense Date: |
9 January 2013 |
| Approval Date: |
24 July 2013 |
| Submission Date: |
1 February 2013 |
| Access Restriction: |
1 year -- Restrict access to University of Pittsburgh for a period of 1 year. |
| Number of Pages: |
146 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
carbon nanomaterial, biosensing |
| Date Deposited: |
24 Jul 2013 20:11 |
| Last Modified: |
15 Nov 2016 14:08 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/17141 |
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