Nanostructured Materials Integrated in Microfabricated Optical Devices
This project combined nanocomposite materials with microfabricated optical device structures for the development of microsensor arrays. For the nanocomposite materials we have designed, developed, and characterized self-assembling, organic/inorganic hybrid optical sensor materials that offer highly selective, sensitive, and reversible sensing capability with unique hierarchical nanoarchitecture. Lipid bilayers and micellar polydiacetylene provided selective optical response towards metal ions (Pb(II), Hg(II)), a lectin protein (Concanavalin A), temperature, and organic solvent vapor. These materials formed as composites in silica sol-gels to impart physical protection of the self-assembled structures, provide a means for thin film surface coatings, and allow facile transport of analytes. The microoptical devices were designed and prepared with two- and four-level diffraction gratings coupled with conformal gold coatings on fused silica. The structure created a number of light reflections that illuminated multiple spots along the silica surface. These points of illumination would act as the excitation light for the fluorescence response of the sensor materials. Finally, we demonstrate an integrated device using the two-level diffraction grating coupled with the polydiacetylene/silica material.