Nanostructured Elasto-Optical Biosensor for Screening on Bioactive Compounds

Biosensors are becoming increasingly important for screening purposes, especially regarding bioactive compounds from nature [1]. In order to parallelize such screening processes, miniaturized sensors are more and more required. In the approach presented here, a so called “elasto-optical“ biosensor, based on nanostructures, is developed to fulfil these demands. The detection principle is based on fluorescence energy transfer (FRET), which takes place between two fluorophors F and F' (Figure). These fluorophores are connected by an elastic spacer consisting of polyethylene glycol units. One end of this spacer is immobilized to an oscillating solid support; the other end is attached to a receptor R, which specifically recognizes bioactive compounds (L), e.g., lectins for sugar recognition [2]. If a ligand binds to a receptor, the oscillation properties of the polyethylene glycol spacer will change and as a consequence, the average distance (D) between F and F' will also change. This will then result in an altered FRET. The elasto-optical biosensor will be capable for screening on bioactive compounds from nature with a molecular weight starting at approx. 500 amu.

Fig. Principle of the elasto-optical biosensor

Acknowledgements: Research was supported by the German BMBF, as part of the program “NanoBiotechnologie“, grant no. 0312022A.

References: 1. Keusgen, M. (2002), NaturWissenschaften 89: 433–444. 2. Hartmann, M., Nikitin, P., Keusgen, M. (2006), Biosens. Bioelectron. (in press).