TITLE SINGLE MOLECULE CONDUCTANCE OF BIOLOGICAL BUILDING BLOCKS: PURINES AND IMIDAZOLE
ABSTRACT: In the last decade, measurements of electron transport in biological molecules such as Deoxyribonucleic acid (DNA) and some proteins have attracted attention as material candidates for molecular electronic applications. Yet, despite numerous studies of electron transport in DNA in particular, inconsistencies in experimental results persist. As results, both the degree and mechanism of charge transport in these biological molecules remains disputed. To understand if different binding configurations of DNA on metal electrodes through unexpected moieties could be responsible for experimental inconsistencies in the literature, investigation on whether small molecules ubiquitous in both nucleic acids and amino acids, such as purines and imidazole, bind to gold electrodes and produce conductance signatures has performed. In this study, Scanning Probe Microscope-based Break Junctions approach has utilized to study single molecule conductance and binding geometry of the purine bases of DNA, particularly adenine and guanine. In addition, the Conductive Atomic Force Microscope-based Break Junction (CAFMBJ) platform has created to simultaneously measure both electrical and mechanical properties of these single molecule junctions. The measurements indicate that purines bind in the junction and display several robust conductance signatures on gold. As results, all adenine and guanine analogs studied here bind through the imidazole, which is identified, for the first time, as a new linker group for single molecule conductance measurements.
COMMITTEE: Advisor, Professor Maria Kamenetska, MSE/Chemistry; Professor Xi Ling, MSE/ChemistryME