A self-assembly technique which relies on capillary forces to organize mono-dispersive silica colloidal spheres was used to fabricate colloidal silica photonic crystals by reliance on a vertical deposition technique. Elaborate photonic crystals were constructed from polystyrene, which can be dissolved in toluene, by templating the solution-cast materials in porous silica photonic structures. After the removal of the template by hydrofluoric acid dissolution, the polymer castings replicated the photonic features and the nanostructure of the master. It was demonstrated that polystyrene in a photonic structure can be used as sensing film, which is potentially valuable in a number of sensing applications based on a change in the average refractive index of the layer medium.

Key words: photonic crystal, silica colloidal crystal, polystyrene, sensing