An　optical　sensor　based　on　the　coupling　between　the　plasmonic　and　photonic　resonance　modes　in　metallic　photonic　crystals　is　investigated.　Large-area　metallic　photonic　crystals　consisting　of　periodically　arranged　gold　nanostructures　with　dimensions　down　to　sub-100　nm　are　fabricated　using　solution-processible　gold　nanoparticles　in　combination　with　interference　lithography　or　interference　ablation,　which　introduces　a　variety　of　fabrication　techniques　for　the　construction　of　this　kind　of　sensor　device.　Sensitivity　of　the　plasmonic　response　of　the　gold　nanostructures　to　the　changes　in　the　environmental　refractive　index　is　enhanced　through　the　coupling　between　the　narrow-band　photonic　resonance　mode　and　the　relatively　broad-band　plasmon　resonance,　which　is　recognized　as　a　Fano-like　effect　and　is　utilized　to　explore　sensors.　Theoretical　modeling　shows　the　characterization　and　the　optimization　of　the　sensitivity　of　this　kind　of　sensor　device.　Theoretical　and　experimental　results　are　demonstrated　for　the　approaches　to　improve　the　sensitivity　of　the　sensor　device.