Sol-gel protective layer for fiberoptic chemical microsensors

The sol-gel-derived materials can be used in construction of various optoel ectronic devices, including optodes of fiberoptic sensors. The porous matri ces provide excellent media for a variety of organic and inorganic compound s, which can serve as detectors. They can work in various environments with different refractive indices. In this study, we report on the influence of the refractive index of external media on the overall performance of the f iberoptic chemical microsensors. Especially, the sensors based on the inten sity measurement are influenced by the refractive index of environment. The application of the sol-gel thin film as a protective layer of microoptode is discussed. The light intensity angular distribution was examined for bot h bare fiber tip, as well as for the tip covered with a sol-gel layer. The magnitude of microsensor response signal was measured, as well. The smaller signal decrease was observed for microoptode covered by sol-gel. A possibl e application of the method described for fiberoptic oxygen microsensor is discussed.