Inspired by nature: Novel biosensors based on an assembly of self-assembling S-layer proteins, aptamers and fluorescence dyes


Inspired by nature: Novel biosensors based on an assembly of self-assembling S-layer proteins, aptamers and fluorescence dyes

Weinert, U.; Pollmann, K.; Strehlitz, B.; Raff, J.

The detection of pharmaceuticals in drinking water and food becomes of increasing relevance. Currently there are only few methods available allowing their reliable detection. These methods are mostly highly complicated and time consuming. Therefore, new techniques are required which enable a fast and easy detection of traces of pharmaceuticals. Biosensors based on natural self-organising biomolecules may provide new approaches for a highly specific detection of pharmaceuticals.

Aim of the presented project is the development of such a sensory layer. Our sensory device consists of S layer proteins, aptamers and fluorescence dyes. The S layer proteins serve as binding matrix, aptamers are used as receptors and fluorescence dyes represent our transducer system.
S layer proteins are structural proteins found in numerous bacteria and almost all archaea. They are able to self-assemble in aqueous solutions and on surfaces forming highly ordered crystalline structure with different symmetries. The proteins expose many COOH and NH2-groups that can be modified and functionalized. Aptamers are short DNA or RNA oligonucleotides which are able to reversibly bind specific analytes due to their 3D-structure. For the optical signal of our sensory layer we use two fluorescence dyes which are able to perform a fluorescence resonance energy transfer (FRET).
This effect is very sensitive and is affected by its environment. In our assembly, fluorescence dyes and aptamers are very close to each other. It is expected that a binding of an analyte to the aptamer will also affect FRET.

Our experiments prove a FRET between two fluorescence dyes linked to S layer proteins in solution and on a surface. In addition, the Anti-Thrombin-aptamer, used as model aptamer, was successfully coupled to S-layer proteins without losing its function. These results provide the basis for the intended sensor concept.

Keywords: FRET; S-layer proteins; sensory layer; aptamers

  • Poster
    bio-inspired Materials, 20.-23.03.2012, Potsdam, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-17571
Publ.-Id: 17571