Transcription Of Quartet Supramolecular Aggregates Into Mesoporous Materials And Their Application

Mesoporous materials, one of the most researched and important nanomaterials,is widely used in various fields, such as catalyst, nanomedicine, battery, environment,phtocatalyst, surfactant theory, based on its special treats like large surface area,2-50 nm nanopores, easy to fabricate. Needless to say, different morphology of mesoprous materials have varies use. Recently, biomolecules have been used to synthesis several novel kinds of mesoporous materials which is useful to elucidate the theory of these biomalecules.In this paper, quadruplexes were selected as benign biomolecule template to prepare several kinds of inorganic nano-materials, and the morphology of these materials have been researched in this article by a series of experiment and the formation theory of these materials have been discussed in this dissertation. The properties of the resulting materials based quadruplexes were also studied. The detailed content is described as follows.(1) 5-guanosine monophosphate(GMP) with Sr2+ ions formed G-quadruplex aggregates were used as supramolecular templates for the fabrication of hierarchical mesoporous silica nanotubes materials here. Mesopores with different diameter were obtained, and some mesopore channels run perpendicularly to the center axis of tube and penetrate right through the outer wall of nanotubes after removing the G-quadruplexes templates. Besides, porous hollow silica spheres were synthesized by alternating some reaction parameters in the process of preparation. All these structures are stable even after high temperature calcinations. The formation mechanism was discussed and proposed, and their structures were characterized by a number of means including, IR spectrum, X-ray diffraction, N2 adsorption-desorption isotherm, transmission electron microscopy(TEM), and scanning electron microscopy(SEM).(2) DNA silicification is useful not only to elucidate the intrinsic nature of the biological organic matrices but also provide means to fabricate new materials. The first DNA silifification reported that Guanidinium and ammonium group possessed molecule had been successfully employed as bridge to connect DNA to silica which makes DNA copied into diverse morphology of porous silica. Afterwards, several attempts had been made to synthesis more kinds of nanomaterials employing DNA astemplates. However, mesoporous single crystal prepared from DNA template have not been available now, and the rich diversity of morphologies in these materials may trigger new developments in catalysis, adsorption, nanotechnology, optoelectronic and photonic device, therefore, there is urgent need to find alternative method to prepare mesoporous single crystal particles. Our aim here is to provide a novel synthetic route to fabricate mesoporous single crystal by G-quadruplex silification.G-quadruplex has received many attentions for its application in the field of cancer-related cell biology, environment, hydrogels, nanomedicine, artificial light chemical dynamic devices and porous materials preparation. Guanosine monophosphate self-associate through Hoogsteen hydrogen bonding and undergo metal ion-mediated quadruplex stacking by cation-dipole interactions, which achieve long range structure by noncovalent interaction, and the peripheral phosphate groups repel to each other and have each tetramer rotated by 30 o which induced a chiral arrangement along the column to form a right-handed 5-GMP-helix. Herein, some novel mesoporous silica single crystals were fabricated employing G-quadruplex as templates. The successful preparation of these novel inorganic nanocrystals would be helpful to open the door of providing alternative ways to prepare more kinds of porous materials.(3)It is reported that folic acid formed quadruplexes have been used as templates to fabricated helix mesoporous nanorods, and several other acid have been used as templates to fabricate polyaniline, poly m-phenylenediamine and polypyrrole.Inspired by theses fabulous works, we decided to synthesis several more kinds of materials employing folic acid formed quadruplex aggregates as templates in this investigation. We have used a series of means to characterize their structure, and it has been found that they manifest different morphologies. The formation mechanism of these materials had been proposed and discussed, meanwhile, compared with the other similar materials. The carbonized polypyrrole was proved to have several kinds of elements by XPS analysis and used as Lithium-ion battery cathode materials in this work.