Bacteria as natural resources for novel materials: Bioinspired nanocomposites for environmental technology


Bacteria as natural resources for novel materials: Bioinspired nanocomposites for environmental technology

Pollmann, K.; Günther, T.; Weinert, U.; Marquard, A.; Raff, J.

Nanoscaled materials comprised of organic and inorganic components are becoming more and more important in nanotechnology due to the diversity of applications. The use of self-assembling organic systems as part of such a hybrid material, serving as template for the fabrication of arrays of inorganic nanoparticles, is an attractive approach for the development of new materials. Especially the proteinaceous bacterial surface layers (S-layers) that envelop bacterial cells are attractive for fabricating and patterning of nanostructures. These proteins are composed of protein monomers with the ability to self-assemble into two-dimensional arrays on interfaces and surfaces. The regular distributed pores of these paracrystalline arrays work as binding sites for various metals and offer ideal structures for the formation of regular distributed metallic nanoclusters of a defined size [1]. Such arrays are very attractive for technical applications ranging from the development of novel catalysts to biomedical applications, the programmed assembly of nanometre scale electronic devices, and optical industry [2]. Another approach is the embedding of S-layer proteins into ceramics thus producing metal binding functionalized nanocomposites [3].

Aim of a current project is the development of novel biosensors. These biosensors are composed of three compounds:

1) Bacterial surface layer; these proteins are used for the nano-structuring of surfaces such as SiO2-wafers or glass; they provide a huge amount of orientated functional groups that can be used for coupling of molecules to the surface, thus introducing a high level of functionality in a small device
2) Aptamers, working as receptors; aptamers are oligonucleotides that specifically bind chemical compounds via their three-dimensional structure; the aptamers are coupled to S-layers
3) Fluorophores for detection, coupled to S-layers; two fluorophores are used as donor/acceptor pair; appropriate excitation/emission spectra and closest proximity permit FRET; FRET is interrupted when the analyte is binding to the aptamers.

Another project is focused on the development of novel photocatalysts for the degradation of organic pollutants in the environment. In this approach, S-layer proteins are used as matrix for synthesis as well as immobilization of phototcatalytic nanoparticles such as ZnO or TiO2. These materials, composed of S-layer coated carriers (e.g. alumina, mica, glass) and ZnO particles deposited on S-layer proteins, showed an enhanced catalytic activity in comparison to commercial ZnO nanopowder.

[1] Wahl, R. et al. (2001). Adv. Materials 13, 736-740
[2] Pollmann, K. et al. (2006). Biotechnol. Adv. 24, 58-68
[3] Raff, J. et al. (2003). Chem. Mater. 15, 240-244

  • Poster
    Chemical Nanotechnology Talks X, 26.-27.01.2010, Frankfurt, Deutschland
  • Lecture (Conference)
    Chemical Nanotechnology Talks X, 26.-27.01.2010, Dresden, Deutschland

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Publ.-Id: 13658