Optical waveguide sensor for monitoring living cell morphology

In the present work a sensor with reverse symmetry is realized by depositing a thin polystyrene film onto nanoporous silica with a refractive index of 1.2. An embossed surface relief grating in the PS film is used as coupling element. As a result, significant changes in the incoupling peak height and peak shape were observed during cell attachment and spreading. It is suggested that the area under the incoupling-peaks reflects the initial cell attachment process, while the mean peak position is mostly governed by the spreading of the cells. Optical waveguide sensors have been used so far to detect biological materials at the surface of the sensor in aqueous cover media. These devices are based on the phenomenon that any change in the refractive index of the cover media shifts the effective refractive index of the surface mode. This change is detected through an evanescent optical field decaying exponentially from the surface of the sensor