DOI
https://doi.org/10.25772/TH5Y-VJ84
Author ORCID Identifier
https://orcid.org/0000-0001-8375-688X
Defense Date
2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Dr. Maryanne Collinson
Abstract
The utilization of nanoporous materials has gained increasing interest due to their surface properties such as high surface area, high electrical conductivity, low density, and well-defined pore morphology. Bimetallic nanoporous electrodes have lately become significant in electrochemical sensing because the secondary metals contribute to the size, shape, composition, surface morphology, physical, and chemical properties resulting in improved sensitivity, catalytic 30 activity, and chemical selectivity in comparison with monometallic counterparts. In connection to this, the potentiometric redox sensing of biomolecules with an improved sensitivity by a factor of ~2 to 4 by platinum (Pt) decorated nanoporous gold (NPG) (NPG-Pt) bimetallic electrodes have been observed. These electrodes were prepared by electrodeposition from solutions containing varying concentrations of Pt-salts and time. More details including bimetallic electrode fabrications, characterizations, and their applications have been discussed in a review. By coating NPG-Pt with Nafion films, these modified electrodes showed greater sensitivity and selectivity for biosensing of redox molecules compared to NPG-Pt itself. Additionally, potentiometric sensing of redox biomolecules has been investigated using biopolymers (e.g., Chitosan, kappa-Carrageenan etc.) modified NPG-Pt electrodes. Furthermore, graphene-TiN composite electrodes were designed to detect ascorbic acid, and nitrate ion respectively. These electrodes were prepared by electrochemically depositing exfoliated graphene oxide onto TiN nanorod arrays formed by Glancing Angle Deposition. The detection of ascorbic acid and nitrate ion was successful and proved better than TiN electrodes. This dissertation will provide a brief overview of the fabrication, characterization, and application of nanocomposite electrodes (NPG-Pt and rGO-TiN) in electrochemical sensing of molecules of biological interests.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
4-19-2024