S-layer templated bioinspired synthesis of silica

Area of Science:

• Biomineralization
• Bioinspired materials science
• Protein-templated silica synthesis

Background:

• Understanding bioinspired silica formation is key to developing novel materials.
• S-layer proteins offer potential as scaffolds due to their ordered structures.
• SbpA from Lysinibacillus sphaericus CCM 2177 is a candidate for templating silica.

Purpose of the Study:

• Investigate SbpA's potential as a catalyst, template, and scaffold for silica.
• Explore factors influencing silica formation on SbpA lattices.
• Characterize the resulting silica structures.

Main Methods:

• S-layer protein SbpA reassembly into p4 lattices.
• Silica layer formation using tetramethoxysilane (TMOS).
• In situ quartz crystal microbalance with dissipation monitoring (QCM-D).
• Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy.
• Chemical modification of S-layer carboxyl groups (EDC/EDA).

Main Results:

• SbpA formed ordered monomolecular lattices (p4 symmetry, 13.1 nm lattice constant).
• Silica deposition was enhanced by phosphate presence (K2HPO4/KH2PO4, pH 7.2).
• Silica deposition increased on SbpA lattices with activated carboxyl groups (EDC).
• FTIR-ATR confirmed amorphous silica gel (SiO2)x.yH2O formation.
• Silica surface concentrations ranged from 4 x 10(-9) to 2 x 10(-8) mol cm(-2).

Conclusions:

• SbpA effectively templates silica formation, creating novel architectures.
• Phosphate and carboxyl group modification significantly influence silica yield.
• SbpA shows promise for bioinspired silica material development.