Fabrication of Tuneable Thickness Silica Films on Solid Surfaces Using Amines and Proteins

Abstract

We report an elegant and simple method to fabricate silica films with controlled thickness and roughness using protein coated solid surfaces as substrates. Bovine serum albumin (BSA) and lysozyme having different inherent charges have been used as model proteins (templates) to fabricate silica films. The formation of silica films was achieved by immobilization of BSA and lysozyme on amine (poly(allylamine) (PAH), poly(ethyleneimine) (PEI) and octadecyl amine (ODA)), coated surfaces, followed by treatment with silica precursors (tetramethoxysilane) under environmentally benign conditions of pH and temperature. BSA adsorbs strongly on hydrophilic surfaces (PAH and PEI coated) via electrostatic interaction, while lysozyme shows greater affinity towards hydrophobic surfaces (ODA coated) via largely hydrophobic interactions. The thickness (12-60 nm) and roughness of the films (1.30-3.75 nm) could be tuned by varying the amount of the adsorbed proteins on the amine-coated surfaces. This simple route to prepare silica films of controlled thickness could have potential application in membrane fabrication, biomedical devices, biosensors and next generation electronic components.

Fabrication, characterisation and performance of hydrophilic and super-hydrophilic silica as cell culture surfaces

“…34,38 This interaction promotes condensation of silica around the protein, which in turn leads to film formation. Analysis of the PS-PANI-GDA-LYZ-SiG surface by AFM showed a coating of interconnected silica particles (1.054 AE 0.057 mm and $1.2 particles per nm 2 ) on the lysozyme treated surface with a Root Mean Square (RMS) roughness of 61.1 AE 3.3 nm (Fig.…”

Biosilica Electrically‐Insulating Layers by Soft Lithography‐Assisted Biomineralisation with Recombinant Silicatein

“…[ 17 ] Proteins such as lysozyme [ 18 ] and bovine serum albumin (BSA) in combination with polyelectrolytes [ 19 ] are utilized to produce silica-coated surfaces, exploiting the amount of charge available at the surface. More biomimetic approaches are developed by few groups by specifi c enzymatic routes.…”

Biomimetic and bioinspired silica: recent developments and applications

“…Particulate silica formation using (a) phosphorylated silaffins, 60 (b) cyclic amines 133,136 and (c) diblock copolymers. 129 Silica coatings produced using (d) proteins + polyamines, 154 (e) R5 peptide, 93 (f) polyethyleneimine (PEI) 137 and (g) poly-2-(dimethylamino)ethyl methacrylate (pDMAEMA). 116,122 Hollow silica tubes (h) 246 and hexagonal silica nanoplates (i,j) 100,103 formed using polylysine.…”