Layer-by-Layer Construction of Ultrathin Hybrid Films with Proteins and Clay Minerals

Abstract

Mono- and multilayered clay mineral−protein films were constructed with the layer-by-layer deposition technique. The clay mineral saponite and three proteins (protamine, lysozyme, and papain) were tested. Multilayers with up to 15−15 alternating layers of saponite and protein were built up on glass, quartz, and ZnSe. In some cases these supports were primed with the poly(diallyldimethylammonium) cation before clay/protein deposition. The deposition process can be followed by UV and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and by atomic force microscopy (AFM). X-ray diffraction (XRD) patterns confirm the regular ordering of the layers. The “average” protein layer has the thickness of single molecules. The thickness of the “average” saponite layer is proportional to the positive charge density of the protein and varies between 0.6 and 3 elementary saponite sheets. The layers of protamine and lysozyme are stable. However, a small amount of papain is lost upon deposition of the subsequent saponite layer. H−D exchange of proteins in the films is fast and reversible.

Organic-inorganic hybrid layer-by-layer electrostatic self-assembled film of cationic dye Methylene Blue and a clay mineral: Spectroscopic and Atomic Force microscopic investigations

“…The resultant transition dipole moment will lead to the appearance of more broadened and diffused absorption spectral profile for higher order aggregates. The absorption spectroscopic results of MB aqueous solution with respect to their different ionic form for the pH range studied (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) here is also summarized in Table 1. Fig.…”

“…However, this LbL self-assembly process is not only restricted to simple polyelectrolytes rather extended to cover wide diversity of materials such as many biological molecules, inorganic nanoparticles and semiconductors, smectites (clay mineral) etc. to organize their molecular assemblies with various tailored properties [8][9][10][11] for technological applications [12,13]. This simple method is also environment-friendly and potentially economic method to engineer the molecular arrangement onto a solid support.…”

Designed Nanostructures of Clay for Controlled Adsorption of Organic Compounds

“…The films have also been prepared by means of alternate adsorption of a cationic polymer and the anionic sheet of an exfoliated clay. [122][123][124][125][126][127] A periodic arrangement of particles with defined shape has been a topic of interests in future applications for sensors, optics and electronics. 127 128 The clay-polymers may be parts of the building blocks, since the density of dopants (functional units) in the interlayer space can be controlled.…”

Food Packaging Applications of Biopolymer‐Based Films

“…Even if such examples of LbL applications are still in some way sourced from petrochemistry, there can be no doubt that tailor-made bio-sourced packaging will soon be developed. This is especially the case considering recent interest in biomolecular architectures with protein assembly [3,43,51,79] and construction of clay-protein ultrathin films [49,57,76]. …”