Polypeptide-Templated Synthesis of Hexagonal Silica Platelets

Abstract

Several studies have demonstrated the use of biomimetic approaches in the synthesis of a variety of inorganic materials. Poly-L-lysine (PLL) promotes the precipitation of silica from a silicic acid solution within minutes. The molecular weight of PLL was found to affect the morphology of the resulting silica precipitate. Larger-molecular weight PLL produced hexagonal silica platelets, whereas spherical silica particles were obtained using low-molecular weight PLL. Here we report on the polypeptide secondary-structure transition that occurs during the silicification reaction. The formation of the hexagonal silica platelets is attributed to the PLL helical chains that are formed in the presence of monosilicic acid and phosphate ions. Hexagonal PLL crystals can also serve as templates in directing the growth of the silica in a manner that generates a largely mesoporous silica phase that is oriented with respect to the protein crystal template.

Continuous-Flow Applications of Silica-Encapsulated Enzymes

“…Silica-encapsulation has proven to be a versatile method for immobilizing biocatalytic activity and is applicable to a wide range of biomolecules. In addition, the morphology of the particles can be controlled by modifying the reaction conditions during silica formation (13,(44)(45)(46). The primary limitation to broad application is the cost of synthesizing peptides required for silica formation.…”

Growth and Form: What is the Aim of Biomineralization?

“…A higher molecularweight PLL produced hexagonal silica platelets, whereas spherical silica particles were obtained using low-molecular-weight PLL. The polypeptide secondary structure transitions were determined from circular dichroism spectra [16]. 12-Amino-acid peptides, when bound to silica nanoparticles, provide the simplest system for synthesizing the starting product, porous silica spheres (see Section …”

Mussel adhesive protein inspired coatings: a versatile method to fabricate silica films on various surfaces

“…In contrast, sponges and diatoms synthesise and fabricate precisely controlled and hierarchically order nano-structured silica materials from soluble silicon species under ambient conditions using special classes of proteins that include silicatein [17][18][19][20] and siliaffins. 21,22 To mimic biosilicification reaction in vitro, many synthetic polypeptides, [23][24][25][26][27][28] polyamines [29][30][31][32][33] and diblock polymers [34][35][36] have been synthesized and used to make silica particles in solution.…”