Transcription of G-quartet supramolecular aggregates into hierarchical mesoporous silica nanotubes

Abstract

The use of 5-guanosine monophosphate (GMP) with Sr(2+) ions to form G-quadruplex bundles as supramolecular templates for the preparation of hierarchical mesoporous silica nanotube materials is reported here, and some mesopores with a diameter of 4-22 nm were obtained. Furthermore, some mesopore channels which run perpendicularly to the center axis of the tube and penetrate right through the outer wall of the nanotubes were achieved by removing the templates. Besides, porous hollow silica spheres were obtained by changing some of the reaction conditions during the process of preparation. Their structures are stable even after high temperature calcination. A formation mechanism was proposed and discussed, and their structures were characterized using a number of means including X-ray diffraction, IR spectra, N2 adsorption-desorption isotherms, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Functional Systems Derived from Nucleobase Self‐assembly

“…In this approach, the Garcia‐Bennett and Xu groups introduced silica source ((3‐aminopropyl)triethoxysilane, APES, and tetraethyl orthosilicate, TEOS) to the pre‐formed bundles of GMP‐quadruplex solutions; electrostatic interaction between the phosphate group in GMP and the amino group in APES induces localization of silica source around the quadruplex for hydrolytic formation of SiO 2 . Analyses based on powder X‐ray diffraction, nitrogen sorption isotherm, and electron microscopy revealed good crystallinity and 1D nano channel in the hydrothermally treated or calcined samples …”

Metal ions confinement defines the architecture of G-quartet, G-quadruplex fibrils and their assembly into nematic tactoids

“…G-ribbon often forms in the absence of metal ions, while G-quadruplex, which consists of the stacking of G-quartets with rotated angle, usually forms in the presence of metal ions (12)(13)(14). As promising building blocks, guanine and its derivatives are usually reported as a versatile template to construct functional materials with ordered structure and tunable properties (15)(16)(17)(18). Specifically, the stacking modes of G-quartets, as well as the twisted or untwisted fibril morphologies that can be generated from them, might have an effect on the properties and functions of assembled aggregates.…”