Functional G-quadruplex for Li-ion battery and piezoelectric sensor

Abstract

In recent years, many studies have been inspired by biomaterials to develop advanced materials. Based on their inherent properties and functions, biomaterials allow researchers to design materials for various purposes. The sophistication, adaptability, biocompatibility of biomaterials are important properties required by modern materials. In particular, DNA has inspired many nanotechnologies through delicate and precise assemblies among biomaterials. G-quadruplex, one of such non- canonical DNA structures, is interesting from the standpoint of material science. G-quadruplex is a complex hierarchical structure rather than a typical double helix structure, and many studies have been conducted on it thanks to its unique structure as well as its characteristics such as stability and ion selectivity. In addition, as the understanding of these G-quadruplex increases, attempts on materials using these features are also increasing. In this thesis, I will describe G-quadruplex materials designed and synthesized for various purposes. Amphiphilic guanine derivatives designed to form stable G-quadruplex were synthesized. Each molecule took the form of a dimer and was designed for its own purpose, such as adjusting the length of the alkyl chain. The molecules synthesized in this way were searched for solvent and salt conditions that could form G-quadruplex. G-quadruplex synthesized under optimal conditions has been proven to be successfully synthesized through various spectroscopic and structural analyses, and in particular, NMR has been used to confirm G-quadruplex formation in solution state and solid state. The relationship between the structure of G-quadruplex and the effect in application when used as a material was confirmed. The ion conduction phenomenon of the G-quadruplex structure was confirmed by using a thermotropic liquid crystal with a G-quadruplex structure with a controlled alkyl chain. In order to analyze the G-quadruplex with different thermal behavior and structural characteristics depending on the alkyl chain, and to use it as a lithium-ion conductor, ion conduction occurred only in columnar G-quadruplex, and this showed the possibility of a safe solid electrolyte that stops ion conduction above a certain temperature range. It was also observed that molecules capable of forming G-quadruplexes in electrolyte solvents can be designed and used as additives to ensure high performance. The G-quadruplex was designed to be used as an additive through acetylation, which increases the solubility and stability of the G-quadruplex. In addition, piezoelectric properties have been analyzed by producing G-quadruplex crystals with special structures and structural stability. By self-assembling molecules of dimer structure connected to two guanines by a linker, a G-quadruplex structure was formed by self-assembling potassium, and thus crystals with piezoelectric properties could be obtained. Finally, using liquid crystal molecules that form a G- quadruplex, an environmentally friendly approach was also presented as piezoelectric materials that can be recycled several times while maintaining their shape, even if they are not polymers.