Estrogen detection in waterish solutions by Silicon based light emitters

Endocrine-disrupting compounds (EDC´s) constitute a wide group of environmental pollutants that causes severe effects on the people and wild life. Actually, considerable interests have been focused on quantification methods for analytical tracing of chemical substances in drinking water, as in food industry, and medical diagnostic.
A sensor concept for estrogen detection in waterish solutions by Silicon based light emitters (MOSLED) was developed. This concept is based on direct fluorescence analysis and consists of a certain arrangement of the bio- components and their fabrication methods as well as the measurement protocol.
The functionalization of the SiO2 surface of the MOSLED was realized by means of the new developed SSC (Spraying Spin Coating) method. The chemical precursors of this method are organofunctional silane groups with three different functional groups, namely the amino-, carboxyl-, and thiolgroups. These results have been compared with those of the literature. The optimization of the SSC-method was analyzed by means of standard surface science techniques like FTIR-, Raman-, and XPS-spectroscopy. The surface roughness was applied by using AFM-spectroscopy, which showed a smooth surface by the samples treated with the SSC-method.
In order to immobilize the hER(alpha) receptor at the surface, the receptor was bound to the molecular shell of the QDot655 dye and finally adsorbed to the silanized SiO2 surfaces. The fraction of the immobilized hER(alpha) receptors was controlled via Photoluminescence-measurements.
The whole concept of the sensor was tested at two water samples containing estrogen in different concentrations.