Biomimetic Synthesis of Silica Nanotubes by Using Short Peptide Self-assemblies as Templates

Objective As for the unique properties of good biocompatibility and excellent optical performance, silica nanotubes have shown potential applications in different fields. The properties of the silica nanotubes were well correlated with their size and morphologies. In order to prepare silica nanotubes with much larger size and expand their applications in different fields, this study selected wide peptide nanotubes as templates for biomimetic synthesis of silica materials. Methods In order to obtain silica nanotubes with relative large size, here we prepared silica nanotubes by using wide nanotubes (with diameters of approximately 40 nm) self-assembled by the bola peptide Ac-KI3VK-CONH2 as templates through a biomimetic mineralization route. The stability of the peptide nanotubes was firstly investigated and the results demonstrated that these nanotubes can be easily destroyed by dilution, addition of organic solvents, or changing the solution pH value, showing poor stability. Then, we chose methyl n-silicate (TMOS) with fast reaction rate as the precursor to prepare silica nanomaterials and systemically explored the influence of different factors on the size and morphology of the silica nanotubes. Results The results demonstrated that the ideal condition for preparing silica nanotubes with uniform shape and size was using TMOS as precursor and keeping its concentration at 1.11%-3.33% (v/v) under neutral or weak alkaline conditions. Conclusion This work successfully prepared silica nanotubes with relative large diameter by using self-assemblies formed by a bola peptide as templates and silicon source with fast reaction rate, which is of great significance and may expand the applications of wide silica nanotubes in different fields.