Synthesis of silica/polypeptide hybrid nanomaterials and mesoporous silica by molecular replication of sheet-like polypeptide complexes through biomimetic mineralization

Abstract

Biomimetic synthesis of silica/polymer hybrid nanomaterials inspired by silica-condensing microorganisms has gained significant advances in recent years and the as-prepared hybrid materials have been explored for a variety of applications. In this work, silica/polypeptide hybrid nanoparticles (NPs) and coating films can be facilely fabricated by silica mineralization of poly(l-lysine)-block-poly(l-threonine)/poly(l-glutamic acid) (PLL-b-PLT/PGA) fibril complexes assembled in solutions or on substrates at benign conditions. The experimental data revealed that PLL-b-PLT can self-assemble to form fibrils via intermolecular hydrogen bonding interactions between PLT chains and, upon complexing with PGA, silicas were efficiently mineralized in both the sheet-like PLL/PGA complexes and PLT domains, resulting in the fabrication of silica/polypeptide hybrid materials. After removing the polypeptides, mesoporous silicas exhibiting pore size between 2 and 10 nm and large pores (>10 nm) were fabricated by the replication of the sheet-like polypeptides and fibril complexes/aggregates, respectively. This study demonstrates that these polypeptide fibril complexes can serve both as nucleating agents and as templates for the fabrication of oxide/polypeptide hybrid NPs, mesoporous oxides and oxide/polypeptide coating films, which have potential applications in a variety of areas.

Keywords: Biomineralization; Chain conformation; Fibrils; Hybrid materials; Mesoporous silica; Polypeptide; β-sheet.