Author ORCID Identifier
https://orcid.org/0009-0002-7615-501X
Date of Award
5-2024
Document Type
Thesis (Ph.D.)
Department or Program
Chemistry
First Advisor
Katherine A. Mirica
Abstract
Layered, conductive framework materials are a class of materials with properties that make them ideal sensing materials in electronic chemical sensors. My thesis is focused on the development of these materials for electrochemical sensing of liquid phase analytes, and on understanding the material–analyte and material–electrode interfaces, and their self-assembly and deposition onto surfaces.
Chapter 1 provides a summary of the use of layered conductive metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) in electronic chemical sensors, detailing the materials and sensor architectures employed, and the analytes detected. Relevant performance metrics are compared, and investigations into material–analyte interactions are highlighted.
Chapter 2 investigates the use of hexahydroxytriphenylene-based MOFs as the working electrode material for voltammetric detection of nitric oxide, comparing the impact of the metal node on electrode sensitivity to NO. A nickel-based material showed sensitivity to NO, but displayed limited stability on a glassy carbon substrate, which was improved by employing a conductive polymer adhesive, highlighting the impact of the MOF-electrode interface on sensing performance. Optimized electrodes detected NO at nanomolar concentrations and exhibited moderate selectivity against potential interferents.
Chapter 3 describes the investigation into the self-assembly of Ni3(HHTP)2, a layered conductive MOF. A novel method for monitoring MOF deposition with ATR-FTIR was developed to study the impact of oxidants on the rate of MOF formation. The presence of oxidants impacted the crystallinity and morphology of the resulting MOF particles, with oxidant-free conditions inhibiting MOF formation, and excesses of oxidant resulting in irregularly shaped particles. The initial phase of Ni3(HHTP)2 self-assembly was identified as the formation of Ni-HHTP coordination complexes in solution, which then assembled into crystalline MOF with the addition of oxidant.
The appendices provide preliminary data that highlight promising future directions: that of exploring phthalocyanine-based frameworks for NO sensing (Appendix A), and that of depositing MOFs onto threads for flexible sensors (Appendix B). Taken together, the chapters of my thesis provide new understanding of the molecular interactions by which layered conductive MOFs self-assemble, adhere to substrates, and interact with analytes, which lays the groundwork for employing these materials in a variety of biosensing applications.
Recommended Citation
Ambrogi, Emma Katherine, "Bridging the Gap Between Molecular Components and Functional Electronic Chemical Sensing Devices with 2D Layered, Conductive Metal–Organic Frameworks" (2024). Dartmouth College Ph.D Dissertations. 238.
https://digitalcommons.dartmouth.edu/dissertations/238