Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

In this report we present our recent developments for utilizing the Si-based light emitter consisting of a MOS structure for the detection of organic pollutants. In the latest approach the light emitters are intended to serve as light sources in smart biosensors [1, 2]. In fluid media the device is placed beneath the dye-labeled sample exciting the dye. This light emission can be recorded by an external detector. It was shown that the silanization of the device surface was successfully based on the covalent binding of the organosilane [3]. The harmlessness of the silanization method to the integrated light emitters was proved by comparing the electroluminescence spectra of Tb-based MOSLEDs before and after silanization. We further showed that the transparency is maintained. Similarly, the human estrogen receptor hERα could be immobilized effectively on the coated surface [3]. We also discuss our concept of an integrated light emitter and a receiver in a dielectric waveguide structure below the bioactive layer for the detection of harmful substances, like synthetic estrogens or plasticizer in drinking water. Optical properties of waveguides, e.g. the transmission, are very sensitive to changes of the effective refraction index, which might be induced by the immobilization of biomolecules on the waveguide surface or in cavity structures, e.g. photonic crystals. This lab-on-a-chip system provides fast light transmission without using of any additional lenses and achieves further portability and miniaturization.

[1] L. Rebohle, C. Cherkouk, S. Prucnal, M. Helm, W. Skorupa, Vacuum 83, 24 (2009)
[2] L. Rebohle, T. Gebel, R.A. Yankov, T. Trautmann, W. Skorupa, J. Sun, G. Gauglitz, R. Frank, Optical Materials 27, 1055 (2005)
[3] C. Cherkouk, L. Rebohle, W. Skorupa, T. Strache, H. Reuther and M. Helm, Journal of Colloid and Interface Science 337, 375 (2009)